MULTIJECT IMM

Indications

• Tuberculosis, resistant to other treatment
• Brucellosis (as an adjunct to doxycycline)
• Severe gram-negative infections (specific cases)

Dosage

Adults: For tuberculosis: 15 mg/kg daily (maximum 1 g per dose), reduce in those under 50 kg and over 40 years. For other infections: 3 mg/kg daily in 3 divided doses, increased if necessary up

Mechanism of action

Streptomycin enters bacterial cells through a three-phase process. Initially, it binds electrostatically to negatively charged components of bacterial cell membranes, increasing permeability and allowing entry. This is followed by energy-dependent transport into the cytoplasm where it binds to the 30S ribosomal subunit, causing mistranslation of proteins and disrupting membrane integrity. The resultant damage leads to concentration-dependent bactericidal effects, including immediate and delayed actions due to impaired protein synthesis.

Pharmacodynamics

Streptomycin has a narrow spectrum of activity, effective against susceptible strains of Yersinia pestis, Francisella tularensis, Brucella, and certain strains of gram-negative bacilli and gram-positive cocci. Resistance has reduced its effectiveness against many pathogens, and it is not effective against Pseudomonas aeruginosa. The drug's therapeutic index is narrow, necessitating close monitoring for toxic effects, particularly nephrotoxicity and ototoxicity.

Pharmacokinetics

Streptomycin is administered parenterally due to poor oral absorption. After intramuscular injection, it achieves peak plasma concentrations within 1-2 hours. It is distributed widely in body tissues and fluids, but does not penetrate well into the central nervous system. The drug is primarily eliminated unchanged by the kidneys, necessitating dosage adjustments in renal impairment. The half-life is approximately 2-3 hours in individuals with normal renal function.

Contra-indications

• Hypersensitivity to streptomycin or other aminoglycosides
• Myasthenia gravis (due to risk of neuromuscular blockade)
• Pregnancy (especially in the second and third trimesters due to risk of auditory or vestibular nerve damage)

Adverse effects

• Nephrotoxicity
• Ototoxicity
• Nausea
• Vomiting
• Diarrhea
• Electrolyte imbalance
• Blood disorders
• Confusion
• Paraesthesia
• Drowsiness
• Respiratory disorders
• Hearing loss
• Vestibular dysfunction

Interactions

• Other nephrotoxic drugs (e.g., vancomycin, furosemide)
• Neuromuscular blocking agents
• Other ototoxic agents

Precautions

• Caution in renal impairment due to increased risk of nephrotoxicity and ototoxicity
• Monitor renal function and auditory function before and during treatment
• Use with caution in patients with existing hearing loss

Pregnancy

There is a risk of auditory or vestibular nerve damage in the infant when aminoglycosides, including streptomycin, are used during the second and third trimesters of pregnancy.

Breast-feeding

Streptomycin is excreted in breast milk; caution is advised when administering to nursing mothers.

Storage

Store below 25°C, protect from light, and keep out of reach of children.

Formulations

• Streptomycin sulfate injection (various concentrations)
• Streptomycin for inhalation (nebulized form)
• Streptomycin oral solution

Indications

• Corticosteroid-responsive conditions
• Autoimmune diseases
• Inflammatory eye conditions
• Certain malignancies
• Chronic inflammatory disorders

Dosage

Children: Refer to the BNF for Children for appropriate paediatric dosing recommendations based on age and weight.

Adults: Refer to the BNF for specific adult dosing guidelines based on the condition being treated. Doses may vary depending on the severity of the condition and the clinical response.

Mechanism of action

Prednisolone binds to the glucocorticoid receptor, resulting in altered gene expression that decreases vasodilation, capillary permeability, and leukocyte migration to sites of inflammation. It inhibits phospholipase A2, reducing the production of arachidonic acid derivatives, and suppresses pro-inflammatory transcription factors such as NF-Kappa B. This results in an anti-inflammatory effect at lower doses and immunosuppressive effects at higher doses.

Pharmacodynamics

Corticosteroids like prednisolone exert their effects by inhibiting pro-inflammatory signals and promoting anti-inflammatory signals through their action on the glucocorticoid receptor. Prednisolone has a relatively short half-life of 2.1 to 3.5 hours, and while it has a wide therapeutic window, long-term use can lead to hypothalamic-pituitary-adrenal axis suppression and increased infection risk.

Pharmacokinetics

Prednisolone is rapidly absorbed and has a short duration of action. Its pharmacokinetics involve extensive metabolism in the liver, primarily through hepatic enzymes, leading to various metabolites. The elimination half-life is approximately 2.1 to 3.5 hours, and it is primarily excreted in the urine. Chronic use can affect circadian rhythms and homeostasis.

Contra-indications

• Known allergy to prednisolone or any of its components
• Systemic fungal infections
• Active tuberculosis
• Untreated bacterial infections

Adverse effects

• Increased susceptibility to infections
• Gastrointestinal disturbances
• Fluid retention
• Hypertension
• Cushing's syndrome
• Osteoporosis
• Mood changes
• Hyperglycemia

Interactions

• Mitotane (Moderate - decreases exposure)
• Rifampicin (Moderate - decreases exposure)
• Cobicistat (Unknown - increases exposure)
• Idelalisib (Unknown - increases exposure)
• Clarithromycin (Unknown - increases exposure)

Precautions

• Monitor for signs of infection during therapy
• Use with caution in patients with a history of gastrointestinal ulcers
• Tapering of dosage may be necessary to avoid withdrawal symptoms
• Consider potential effects on growth in pediatric patients

Pregnancy

Prednisolone is classified as a Category C drug. It should only be used if the potential benefits justify the potential risk to the fetus.

Breast-feeding

Prednisolone is excreted in breast milk. Caution should be exercised when administered to nursing mothers.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Tablets: 2 mg, 4 mg, 16 mg, 100 mg
• Suspension for injection
• Powder and solvent for solution for injection

Indications

• Bowel sterilization before surgery
• Hepatic coma
• Topical infections caused by susceptible organisms

Dosage

Children: Refer to the BNF for Children for appropriate dosing information.

Adults: By mouth: 1 g every 1 hour for 4 hours, then 1 g every 4 hours for 2–3 days. For hepatic coma: Up to 4 g daily in divided doses usually for 5–7 days.

Mechanism of action

Neomycin sulfate binds to the 30S ribosomal subunit of bacteria, leading to the misreading of mRNA and the inhibition of protein synthesis. This disrupts the production of essential proteins needed for bacterial growth and function, ultimately resulting in cell death.

Pharmacodynamics

Neomycin demonstrates bactericidal activity against susceptible bacteria. Its efficacy is enhanced in alkaline environments, which is why it is often used in combination with other agents for surgical prophylaxis. The drug is primarily effective against a range of gram-negative organisms, including Escherichia coli and Klebsiella species, but also has some activity against gram-positive organisms.

Pharmacokinetics

Neomycin is poorly absorbed from the gastrointestinal tract, and its systemic absorption is minimal when administered orally. In cases of systemic use, such as intramuscular or intravenous administration, neomycin is distributed widely in the body but is primarily excreted unchanged in the urine. The elimination half-life varies but is generally around 2 to 3 hours in individuals with normal renal function. Monitoring of serum concentrations is essential to prevent toxicity, especially in patients with renal impairment.

Adverse effects

• neurotoxicity
• ototoxicity
• nephrotoxicity
• allergic reactions
• skin rashes
• hearing loss

Interactions

• other nephrotoxic drugs
• loop diuretics
• neuromuscular blocking agents

Precautions

• monitor renal function
• use cautiously in patients with hearing impairment
• avoid concurrent use with other ototoxic medications
• ensure adequate hydration

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use caution; neomycin can be absorbed systemically and may affect the nursing infant.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• oral tablets
• topical ointments
• injectable solutions

Indications

• Bacterial infections caused by aerobic organisms
• Topical treatment of skin infections

Mechanism of action

Neomycin binds to specific proteins and 16S rRNA within the 30S ribosomal subunit of susceptible bacteria. This binding interferes with the decoding site, causing misreading of mRNA and leading to the incorporation of incorrect amino acids into polypeptides. As a result, nonfunctional or toxic peptides are produced, and polysomes are disrupted into nonfunctional monosomes. Neomycin's bactericidal action is characterized by its ability to irreversibly bind to the 30S ribosomal subunit, thereby inhibiting bacterial protein synthesis.

Pharmacodynamics

Neomycin is primarily active against aerobic bacteria and is not effective against fungi, viruses, or most anaerobic bacteria. It mediates its bactericidal effects by inhibiting protein synthesis, which suppresses bacterial growth and survival. Following oral administration, neomycin exhibits a duration of bactericidal activity lasting between 48 to 72 hours. It is particularly useful in treating infections caused by strains of E. coli and Klebsiella, and it also acts to reduce colonic bacterial populations in patients with hepatic coma.

Pharmacokinetics

Neomycin is poorly absorbed from the gastrointestinal tract when taken orally, which limits its systemic availability and enhances its utility in targeting colonic bacteria. It is generally not used parenterally due to its potential for nephrotoxicity and ototoxicity. The duration of action following oral administration can last from 48 to 72 hours, and it is primarily excreted unchanged in the urine. Caution should be exercised when using neomycin in patients with renal impairment, as the risk of toxicity increases.

Adverse effects

• Nephrotoxicity
• Ototoxicity
• Allergic reactions
• Diarrhea
• Nausea
• Vomiting

Interactions

• neomycin+digoxin: Unknown (decreases absorption)
• neomycin+sorafenib: Unknown (decreases exposure)

Precautions

• Use with caution in patients with renal impairment
• Monitor renal function during therapy
• Evaluate hearing function in long-term use

Pregnancy

Neomycin is classified as category D; it should be used only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Neomycin is excreted in breast milk; caution should be exercised when administered to nursing mothers.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Topical ointment
• Cream
• Eye drops
• Oral tablets

Indications

• Bacterial infections
• Pneumonia
• Streptococcal infections
• Syphilis
• Meningitis
• Endocarditis
• Skin infections

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations based on the type of penicillin and indication.

Adults: Refer to the BNF for specific dosing recommendations based on the type of penicillin and indication.

Mechanism of action

Penicillin targets penicillin-binding proteins (PBPs) located inside the bacterial cell wall. By binding to these proteins, penicillin disrupts the transpeptidation process, which is essential for cell wall structural integrity. This results in weakened cell walls, causing osmotic instability and ultimately leading to cell lysis and death.

Pharmacodynamics

Penicillin exhibits bactericidal activity, meaning that it kills bacteria rather than merely inhibiting their growth. Its effectiveness is generally dependent on the growth phase of the bacteria, as it is most active against actively dividing cells. The spectrum of activity varies among different penicillins, with some being more effective against specific bacterial strains.

Pharmacokinetics

Penicillin is primarily absorbed in the gastrointestinal tract, with its bioavailability varying depending on the specific type of penicillin. It is primarily excreted by the kidneys, with a half-life that typically ranges from 30 minutes to 2 hours, depending on the formulation. Dosage adjustments may be necessary in patients with renal impairment to prevent accumulation and toxicity.

Contra-indications

• History of hypersensitivity to penicillins
• Severe allergic reactions to beta-lactam antibiotics

Adverse effects

• Allergic reactions such as rash, urticaria, and anaphylaxis
• Gastrointestinal disturbances including nausea, vomiting, and diarrhea
• Superinfection due to alteration of normal flora
• Hematologic reactions such as leukopenia, thrombocytopenia

Interactions

• valproate+penicillins: Severe (increases risk of adverse effects)
• allopurinol+penicillins: Unknown (increases risk of skin rash)
• leflunomide+penicillins: Unknown (increases exposure)
• nitisinone+penicillins: Unknown (increases exposure)
• penicillins+phenindione: Unknown (increases risk of bleeding events)
• teriflunomide+penicillins: Unknown (increases exposure)

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of allergic reactions
• Consider alternative therapy in patients with a history of severe allergies

Pregnancy

Penicillins are generally considered safe to use during pregnancy; however, consult local guidelines and assess benefits versus risks.

Breast-feeding

Penicillins are excreted in breast milk in small amounts; generally considered safe, but monitor infant for possible effects.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablets
• Oral suspension
• Intravenous injection
• Intramuscular injection

Indications

• Local anesthesia for dental procedures
• Regional anesthesia for minor surgical interventions
• Pain relief in localized areas

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Procaine acts mainly by inhibiting sodium influx through voltage-gated sodium channels in the neuronal cell membrane of peripheral nerves. By interrupting sodium influx, the generation of action potentials is inhibited, thereby blocking signal conduction. Procaine also interacts with N-methyl-D-aspartate (NMDA) receptors, nicotinic acetylcholine receptors, and serotonin receptor-ion channel complexes, contributing to its anesthetic effects. It reduces membrane permeability to both sodium and potassium ions, increasing the electrical excitability threshold and slowing impulse conduction.

Pharmacodynamics

Procaine is indicated for producing local or regional anesthesia, particularly in oral surgery. Its vasoconstrictive properties help minimize blood loss during procedures. As an ester anesthetic, procaine is metabolized in the plasma by pseudocholinesterase, leading to the formation of para-aminobenzoic acid (PABA), which is excreted in urine. Compared to other local anesthetics like lidocaine, procaine has a unique profile that can be beneficial in specific surgical contexts.

Pharmacokinetics

Procaine is rapidly metabolized in the bloodstream, with its effects typically lasting for a short duration. The onset of anesthesia is relatively quick, but the duration of action is shorter than that of other longer-acting local anesthetics. The primary route of elimination for procaine and its metabolites is renal excretion. The pharmacokinetics can be influenced by factors such as the site of injection and the presence of vasoconstrictors.

Contra-indications

• Hypersensitivity to procaine or other local anesthetics
• Severe liver or kidney disease
• Myasthenia gravis

Adverse effects

• Allergic reactions including rash and anaphylaxis
• Nausea and vomiting
• Dizziness
• Headache
• Cardiovascular effects such as arrhythmias
• Nerve damage or prolonged numbness at the injection site

Interactions

• Increased risk of systemic toxicity when used with other local anesthetics
• Potential interaction with cholinesterase inhibitors
• May enhance the effects of other CNS depressants

Precautions

• Use with caution in patients with cardiovascular disease
• Careful monitoring is required in patients with a history of seizures
• Avoid use in patients with significant hypovolemia

Pregnancy

Procaine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult local guidelines and conduct a risk assessment.

Breast-feeding

Procaine is excreted in breast milk; caution should be exercised when administering to nursing mothers.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Injection solution

Mechanism of action

The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. Although altered homeostatic regulation, including disturbance of 24-h rhythms, is often observed in the patients undergoing glucocorticoid therapy, the mechanisms underlying the disturbance remains poorly understood. We report here that chronic treatment with a synthetic glucocorticoid, prednisolone, can cause alteration of circadian clock function at molecular level. Treatment of cultured hepatic cells (HepG2) with prednisolone induced expression of Period1 (Per1), and the prednisolone treatment also attenuated the serum-induced oscillations in the expression of Period2 (Per2), Rev-erbalpha, and Bmal1 mRNA in HepG2 cells. Because the attenuation of clock gene oscillations was blocked by pretreating the cells with a Per1 antisense phosphothioate oligodeoxynucleotide, the extensive expression of Per1 induced by prednisolone may have resulted in the reduced amplitude of other clock gene oscillations. Continuous administration of prednisolone into mice constitutively increased the Per1 mRNA levels in liver and skeletal muscle, which seems to attenuate the oscillation in the expressions of Per2, Rev-erbalpha, and Bmal1. However, a single daily administration of prednisolone at the time of day corresponding to acrophase of endogenous glucocorticoid levels had little effect on the rhythmic expression of clock genes. These results suggest a possible pharmacological action by prednisolone on the core circadian oscillation mechanism and indicate the possibility that the alteration of clock function induced by prednisolone can be avoided by optimizing the dosing schedule. Glucocorticoids are capable of suppressing the inflammatory process through numerous pathways. They interact with specific intracellular receptor proteins in target tissues to alter the expression of corticosteroid-responsive genes. Glucocorticoid-specific receptors in the cell cytoplasm bind with steroid ligands to form hormone-receptor complexes that eventually translocate to the cell nucleus. There these complexes bind to specific DNA sequences and alter their expression. The complexes may induce the transcription of mRNA leading to synthesis of new proteins. Such proteins include lipocortin, a protein known to inhibit PLA2a and thereby block the synthesis of prostaglandins, leukotrienes, and PAF. Glucocorticoids also inhibit the production of other mediators including AA metabolites such as COX, cytokines, the interleukins, adhesion molecules, and enzymes such as collagenase. /Glucocorticoids/

Pharmacodynamics

Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisolone has a short duration of action as the half life is 2.1-3.5 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections.

Mechanism of action

There are 3 key phases of aminoglycoside entry into cells. The first “ionic binding phase” occurs when polycationic aminoglycosides bind electrostatically to negatively charged components of bacterial cell membranes including with lipopolysaccharides and phospholipids within the outer membrane of Gram-negative bacteria and to teichoic acids and phospholipids within the cell membrane of Gram-positive bacteria. This binding results in displacement of divalent cations and increased membrane permeability, allowing for aminoglycoside entry. The second “energy-dependent phase I” of aminoglycoside entry into the cytoplasm relies on the proton-motive force and allows a limited amount of aminoglycoside access to its primary intracellular target - the bacterial 30S ribosome. This ultimately results in the mistranslation of proteins and disruption of the cytoplasmic membrane. Finally, in the “energy-dependent phase II” stage, concentration-dependent bacterial killing is observed. Aminoglycoside rapidly accumulates in the cell due to the damaged cytoplasmic membrane, and protein mistranslation and synthesis inhibition is amplified. Hence, aminoglycosides have both immediate bactericidal effects through membrane disruption and delayed bactericidal effects through impaired protein synthesis; observed experimental data and mathematical modeling support this two-mechanism model. Inhibition of protein synthesis is a key component of aminoglycoside efficacy. Structural and cell biological studies suggest that aminoglycosides bind to the 16S rRNA in helix 44 (h44), near the A site of the 30S ribosomal subunit, altering interactions between h44 and h45. This binding also displaces two important residues, A1492 and A1493, from h44, mimicking normal conformational changes that occur with successful codon-anticodon pairing in the A site. Overall, aminoglycoside binding has several negative effects including inhibition of translation, initiation, elongation, and ribosome recycling. Recent evidence suggests that the latter effect is due to a cryptic second binding site situated in h69 of the 23S rRNA of the 50S ribosomal subunit. Also, by stabilizing a conformation that mimics correct codon-anticodon pairing, aminoglycosides promote error-prone translation. Mistranslated proteins can incorporate into the cell membrane, inducing the damage discussed above. The primary intracellular site of action of the aminoglycosides is the 30 S ribosomal subunit, which consists of 21 proteins and a single 16 S molecule of RNA. at least three of these proteins and perhaps the 16 S ribosomal RNA as well contribute to the streptomycin binding site, and alterations of these molecules markedly affect the binding and subsequent action of streptomycin. For example, a single amino acid substitution of asparagine for lysine at position 42 of one ribosomal protein (S12) prevents binding of the drug; the resultant mutant is totally resistant to streptomycin. Another mutant, in which glutamine is the amino acid at this position, is dependent on streptomycin. During protein synthesis, the ribosome selects aminoacyl-transfer RNAs with anticodons matching the messenger RNA codon present in the A site of the small ribosomal subunit. The aminoglycoside antibiotic streptomycin disrupts decoding by binding close to the site of codon recognition. Here we use X-ray crystallography to define the impact of streptomycin on the decoding site of the Thermus thermophilus 30S ribosomal subunit in complexes with cognate or near-cognate anticodon stem-loop analogues and messenger RNA. Our crystal structures display a significant local distortion of 16S ribosomal RNA induced by streptomycin, including the crucial bases A1492 and A1493 that participate directly in codon recognition. Consistent with kinetic data, we observe that streptomycin stabilizes the near-cognate anticodon stem-loop analogue complex, while destabilizing the cognate anticodon stem-loop analogue complex. These data reveal ho

Pharmacodynamics

Although streptomycin originally had broad gram-negative and gram-positive coverage, its spectrum of activity has been significantly narrowed due to antibiotic resistance. Streptomycins current spectrum of activity includes susceptible strains of Yersinia pestis, Francisella tularensis, Brucella, Calymmatobacterium granulomatis, H. ducreyi, H. influenza, K. pneumoniae pneumonia, E.coli, Proteus, A. aerogenes, K. pneumoniae, Enterococcus faecalis, Streptococcus viridans, Enterococcus faecalis, and Gram-negative bacillary bacteremia. Streptomycin is not reliably active against pseudomonas aeruginosa. Similar to other aminoglycosides, streptomycin is considered to have a narrow therapeutic index. Characteristic toxicities of streptomycin include nephrotoxicity and ototoxicity. Patients should be carefully monitored for early signs of hearing loss and vestibular dysfunction in order to prevent permanent damage to sensorineural cells. Neuromuscular blockade has also been rarely reported.

Mechanism of action

Framycetin binds to specific 30S-subunit proteins and 16S rRNA, four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site in the vicinity of nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes. Like other aminoglycoside antibiotic drugs, neomycin inhibits bacterial ribosomes by binding to the 30S ribosomal subunit of susceptible bacteria and disrupting the translational machinery of bacterial protein synthesis. Bacterial translation is normally initiated by the mRNA binding to the 30S ribosomal subunit and subsequent binding with 50S subunit for elongation. Aminoglycosides are usually bactericidal in action. Although the exact mechanism of action has not been fully elucidated, the drugs appear to inhibit protein synthesis in susceptible bacteria by irreversibly binding to 30S ribosomal subunits. /Aminoglycosides/ A class of angiogenesis inhibitor has emerged from our mechanistic study of the action of angiogenin, a potent angiogenic factor. Neomycin, an aminoglycoside antibiotic, inhibits nuclear translocation of human angiogenin in human endothelial cells, an essential step for angiogenin-induced angiogenesis. The phospholipase C-inhibiting activity of neomycin appears to be involved, because U-73122, another phospholipase C inhibitor, has a similar effect. In contrast, genistein, oxophenylarsine, and staurosporine, inhibitors of tyrosine kinase, phosphotyrosine phosphatase, and protein kinase C, respectively, do not inhibit nuclear translocation of angiogenin. Neomycin inhibits angiogenin-induced proliferation of human endothelial cells in a dose-dependent manner. At 50 microM, neomycin abolishes angiogenin-induced proliferation but does not affect the basal level of proliferation and cell viability. Other aminoglycoside antibiotics, including gentamicin, streptomycin, kanamycin, amikacin, and paromomycin, have no effect on angiogenin-induced cell proliferation. Most importantly, neomycin completely inhibits angiogenin-induced angiogenesis in the chicken chorioallantoic membrane at a dose as low as 20 ng per egg. These results suggest that neomycin and its analogs are a class of agents that may be developed for anti-angiogenin therapy. ... Aminoglycosides are aminocyclitols that kill bacteria by inhibiting protein synthesis as they bind to the 16S rRNA and by disrupting the integrity of bacterial cell membrane. Aminoglycoside resistance mechanisms include: (a) the deactivation of aminoglycosides by N-acetylation, adenylylation or O-phosphorylation, (b) the reduction of the intracellular concentration of aminoglycosides by changes in outer membrane permeability, decreased inner membrane transport, active efflux, and drug trapping, (c) the alteration of the 30S ribosomal subunit target by mutation, and (d) methylation of the aminoglycoside binding site. ... /Aminoglycosides/

Pharmacodynamics

Framycetin is used for the treatment of bacterial eye infections such as conjunctivitis. Framycetin is an antibiotic. It is not active against fungi, viruses and most kinds of anaerobic bacteria. Framycetin works by binding to the bacterial 30S ribosomal subunit, causing misreading of t-RNA, leaving the bacterium unable to synthesize proteins vital to its growth. Framycetin is useful primarily in infections involving aerobic bacteria bacteria. Neomycin mediates its bactericidal action by inhibiting bacterial protein synthesis, thereby suppressing the growth and survival of susceptible bacteria. Following oral administration, the duration of bactericidal activity of neomycin ranged from 48 to 72 hours. By decreasing colonic bacteria that produce ammonia, neomycin was shown to be effective as an adjunctive therapy in hepatic coma to improve neurologic symptoms. Neomycin is active against both gram positive and gram negative organisms, including the major _E. coli_ species resident in the colon as well as the enteropathogenic forms of _E. coli_. It is also active against _Klebsiella_-_Enterobacter_ group. Resistant strains of _E. coli_, _Klebsiella_ and _Proteus spp_. may emerge from neomycin therapy. Neomycin has no antifungal activity and has some activity against some protozoa.

Mechanism of action

Procaine acts mainly by inhibiting sodium influx through voltage gated sodium channels in the neuronal cell membrane of peripheral nerves. When the influx of sodium is interrupted, an action potential cannot arise and signal conduction is thus inhibited. The receptor site is thought to be located at the cytoplasmic (inner) portion of the sodium channel. Procaine has also been shown to bind or antagonize the function of N-methyl-D-aspartate (NMDA) receptors as well as nicotinic acetylcholine receptors and the serotonin receptor-ion channel complex. LOCAL ANESTHETICS BLOCK CONDUCTION BY DECREASING OR PREVENTING THE LARGE TRANSIENT INCREASE IN THE PERMEABILITY OF EXCITABLE MEMBRANES TO SODIUM IONS THAT NORMALLY IS PRODUCED BY A SLIGHT DEPOLARIZATION OF THE MEMBRANE. /LOCAL ANESTHETIC/ LOCAL ANESTHETICS BLOCK CONDUCTION IN NERVE PERHAPS BY COMPETING WITH CALCIUM @ SOME SITE THAT CONTROLS PERMEABILITY OF MEMBRANE. ... LOCAL ANESTHETICS ALSO REDUCE PERMEABILITY OF RESTING NERVE TO POTASSIUM AS WELL AS TO SODIUM IONS. /LOCAL ANESTHETICS/ AS THE ANESTHETIC ACTION PROGRESSIVELY DEVELOPS IN A NERVE, THE THRESHOLD FOR ELECTRICAL EXCITABILITY GRADUALLY INCREASES, THE RATE OF RISE OF THE ACTION POTENTIAL DECLINES, IMPULSE CONDUCTION SLOWS, & THE SAFETY FACTOR FOR CONDUCTION DECREASES; THESE FACTORS DECREASE THE PROBABILITY OF PROPAGATION OF THE ACTION POTENTIAL, AND NERVE CONDUCTION FAILS. /LOCAL ANESTHETICS/ POSTSYNAPTIC ACTION ... END-PLATE CURRENT IS MUCH PROLONGED BY PROCAINE. SIMILARLY, WHEN ... ADDED TO FLUID PERFUSING GANGLION, PREGANGLIONIC STIMULATION FAILS TO ELICIT POSTGANGLIONIC DISCHARGES & GANGLION CELLS BECOME INSENSITIVE TO STIMULATION BY ACETYLCHOLINE. IN ADDITION TO BLOCKING CONDITIONS IN NERVE AXONS IN THE PERIPHERAL NERVOUS SYSTEM, LOCAL ANESTHETICS INTERFERE WITH THE FUNCTION OF ALL ORGANS IN WHICH CONDUCTION OR TRANSMISSION OF IMPULSES OCCURS. ... EFFECTS ON ... CNS, THE AUTONOMIC GANGLIA, THE NEUROMUSCULAR JUNCTION, & ALL FORMS OF MUSCLE. /LOCAL ANESTHETICS/

Pharmacodynamics

Procaine is an anesthetic agent indicated for production of local or regional anesthesia, particularly for oral surgery. Procaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine. Procaine is an ester anesthetic. It is metabolized in the plasma by the enzyme pseudocholinesterase through hydrolysis into para-aminobenzoic acid (PABA), which is then excreted by the kidneys into the urine.