PENIKAN P

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

• Streptococcal infections
• Pneumococcal infections
• Syphilis
• Skin and soft tissue infections
• Respiratory tract infections
• Bone infections (osteomyelitis)

Dosage

Children: Refer to the BNF for Children for specific paediatric dosing guidelines.

Adults: Refer to the BNF for specific adult dosing guidelines.

Mechanism of action

Benzylpenicillin exerts its antibacterial effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, leading to the disruption of peptidoglycan cross-linking. This ultimately results in cell lysis and death of the susceptible bacteria.

Pharmacodynamics

Benzylpenicillin demonstrates time-dependent antibacterial activity. Its efficacy is determined by the duration that the drug concentration remains above the minimum inhibitory concentration (MIC) for the target organism. It is primarily effective against gram-positive cocci, some gram-negative cocci, and non-beta-lactamase producing strains of organisms.

Pharmacokinetics

Benzylpenicillin procaine is administered intramuscularly, with procaine facilitating a slower release of benzylpenicillin into the bloodstream. Following injection, peak plasma concentrations occur within a few hours. It is widely distributed in body tissues and fluids, although it does not penetrate well into the central nervous system unless the meninges are inflamed. Benzylpenicillin is primarily excreted unchanged in the urine, with a half-life varying between 30 minutes to 1 hour, depending on renal function.

Contra-indications

• Hypersensitivity to penicillins or any components of the formulation
• Severe renal impairment
• History of allergic reactions to beta-lactam antibiotics

Adverse effects

• Allergic reactions (e.g., rash, anaphylaxis)
• Gastrointestinal disturbances (e.g., nausea, vomiting, diarrhea)
• Superinfection due to antibiotic resistance
• Neurotoxicity (with rapid intravenous administration)
• Hematologic reactions (e.g., eosinophilia, thrombocytopenia)

Interactions

• Probenecid may increase benzylpenicillin levels by inhibiting renal excretion
• Concurrent use with other nephrotoxic agents may increase the risk of renal impairment
• Antibiotic effects may be reduced when used with bacteriostatic agents such as tetracyclines or sulfonamides

Precautions

• Assess for history of penicillin allergy prior to administration
• Monitor renal function in patients with pre-existing kidney disease
• Caution in patients with a history of asthma or allergic conditions

Pregnancy

Benzylpenicillin is generally considered safe to use during pregnancy. However, it should be prescribed only if clearly needed and after assessing risks versus benefits.

Breast-feeding

Benzylpenicillin is excreted in breast milk in small amounts. It is usually considered safe during breastfeeding, but monitoring for any adverse effects in the infant is advisable.

Storage

Store in a cool, dry place, away from light. Reconstituted solutions should be used immediately or stored in the refrigerator and used within 24 hours.

Formulations

• Benzylpenicillin procaine injection
• Benzylpenicillin procaine powder for injection

Indications

• Serious infections caused by aerobic Gram-negative bacteria
• Infections due to mycobacteria, including tuberculosis
• Endocarditis in conjunction with penicillin-related antibiotics

Dosage

Children: Refer to BNF for Children for specific dosing information, as it is determined by weight and age.

Adults: Refer to BNF for specific dosing information, as it varies based on the type and severity of the infection.

Mechanism of action

Kanamycin irreversibly binds to specific proteins and 16S rRNA of the 30S ribosomal subunit. This binding interferes with the decoding site, leading to misreading of mRNA, incorrect amino acid insertion into peptides, and disruption of polysomes into nonfunctional monosomes. This bactericidal action results in the inhibition of protein synthesis in susceptible microorganisms.

Pharmacodynamics

Kanamycin is effective primarily against aerobic Gram-negative bacteria and some mycobacteria, including those causing tuberculosis. It disrupts the integrity of the bacterial cell membrane and inhibits protein synthesis, rendering bacteria unable to grow and replicate. While it can be used for Gram-positive infections, other antibiotics are usually preferred due to their higher potency and lower toxicity.

Pharmacokinetics

Kanamycin is administered parenterally, as it is poorly absorbed from the gastrointestinal tract. It demonstrates a volume of distribution that is primarily extracellular. The drug is primarily eliminated by the kidneys through glomerular filtration, necessitating dose adjustments in patients with renal impairment. Kanamycin's half-life is approximately 2 to 3 hours in individuals with normal renal function.

Contra-indications

• Hypersensitivity to kanamycin or any aminoglycoside antibiotic
• Severe renal impairment
• Myasthenia gravis

Adverse effects

• Nephrotoxicity
• Ototoxicity (hearing loss, vestibular toxicity)
• Neuromuscular blockade
• Allergic reactions (skin rash, itching)
• Gastrointestinal disturbances (nausea, vomiting)

Interactions

• Other nephrotoxic drugs (e.g., cisplatin, vancomycin) may increase the risk of renal toxicity
• Neurotoxins may potentiate neuromuscular blockade
• Concurrent use with diuretics (e.g., furosemide) may enhance ototoxicity

Precautions

• Monitor renal function regularly during treatment
• Use with caution in patients with pre-existing hearing loss
• Adjust dosage in cases of renal impairment
• Ensure adequate hydration to minimize risk of nephrotoxicity

Pregnancy

Kanamycin is classified as category D. It should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Kanamycin is excreted in breast milk. Caution is advised when administering to nursing mothers.

Storage

Store in a cool, dry place away from light. Refrigeration may be required for some formulations.

Formulations

• Kanamycin sulfate injection
• Kanamycin oral solution

Mechanism of action

Aminoglycosides like kanamycin "irreversibly" bind to specific 30S-subunit proteins and 16S rRNA. Specifically Kanamycin binds to 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. Kanamycin, an aminoglycoside, acts by inhibiting the synthesis of protein in susceptible microorganisms. It is bactericidal in vitro against Gram-negative bacteria and certain Gram-positive bacteria. 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/ ... 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

Kanamycin is an aminoglycoside antibiotic. Aminoglycosides work by binding to the bacterial 30S ribosomal subunit, causing misreading of t-RNA, leaving the bacterium unable to synthesize proteins vital to its growth. Aminoglycosides are useful primarily in infections involving aerobic, Gram-negative bacteria, such as Pseudomonas, Acinetobacter, and Enterobacter. In addition, some mycobacteria, including the bacteria that cause tuberculosis, are susceptible to aminoglycosides. Infections caused by Gram-positive bacteria can also be treated with aminoglycosides, but other types of antibiotics are more potent and less damaging to the host. In the past the aminoglycosides have been used in conjunction with penicillin-related antibiotics in streptococcal infections for their synergistic effects, particularly in endocarditis. Aminoglycosides are mostly ineffective against anaerobic bacteria, fungi and viruses.

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.