XENDA 100

Indications

• Skin disinfection
• Preparation of skin before injections
• Cleansing minor wounds

Dosage

Children: Apply to the skin as required; consult product literature for specific guidance.

Adults: Apply to the skin as required for disinfection.

Mechanism of action

Alcohol exerts its antiseptic effect by denaturing proteins, disrupting cell membranes, and dehydrating microbial cells, leading to cell lysis and death.

Pharmacodynamics

Alcohol has broad-spectrum antimicrobial activity, effective against bacteria, fungi, and viruses. Its efficacy is influenced by concentration, with higher concentrations generally being more effective.

Pharmacokinetics

Alcohol is rapidly absorbed through the skin and mucous membranes. It is metabolized primarily in the liver, with a half-life that varies based on the individual's metabolic rate and the amount consumed.

Contra-indications

• Concomitant use with lithium
• Regular use in neonates
• Patients with severe burns when diathermy has been preceded by application of alcoholic skin disinfectants

Adverse effects

• Eye erythema
• Punctate keratitis
• Cytotoxicity
• Eye discolouration

Interactions

• Increases risk of visual disturbances with antiepileptics
• Increases concentration with methylphenidate
• Increases risk of facial flushing and skin irritation with topical pimecrolimus
• Increases concentration with retinoids
• Increases concentration with acitretin
• Increases risk of facial flushing and skin irritation with topical tacrolimus
• Decreases antidiuretic effect with vasopressin

Precautions

• Avoid regular application to inflamed or broken skin or mucosa
• Avoid broken skin
• Flammable

Pregnancy

Sufficient iodine may be absorbed to affect the fetal thyroid in the second and third trimester.

Breast-feeding

Avoid regular or excessive use.

Storage

Store in a cool, dry place away from heat and direct sunlight.

Formulations

• Betadine 2.5% dry powder spray
• Industrial methylated spirit
• Povidone-Iodine 25 mg per 1 gram

Indications

• Cerebral edema
• Elevated intracranial pressure
• Acute kidney injury
• Oliguria
• Glaucoma
• Renal function diagnostic aid

Dosage

Adults: For cerebral edema, administer 0

Mechanism of action

Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma. This action reduces cerebral edema and intracranial pressure. As a diuretic, it increases the osmolality of glomerular filtrate, leading to increased urinary excretion of water and preventing sodium and chloride reabsorption in the renal tubules. Mannitol also facilitates the urinary excretion of toxic substances and can help in assessing renal function by measuring glomerular filtration rate (GFR).

Pharmacodynamics

Mannitol is classified as an osmotic diuretic. It is chemically similar to other sugar alcohols but has a unique ability to promote diuresis by remaining unabsorbed in the renal tubules. Its use is indicated for conditions associated with increased body fluids, such as cerebral edema and glaucoma. Mannitol may be combined with other diuretics to enhance diuretic efficacy. Inhaled formulations are used in cystic fibrosis, though they may cause bronchospasm and hemoptysis.

Pharmacokinetics

Mannitol is freely filtered by the glomeruli with less than 10% tubular reabsorption, which allows for its urinary excretion rate to serve as a measurement of GFR. It does not undergo significant metabolism and is eliminated primarily through the kidneys. The onset of action occurs within 30 to 60 minutes after intravenous administration, with effects lasting for several hours. Administration may require monitoring of renal function and fluid balance.

Contra-indications

• Anuria
• Severe dehydration
• Severe renal impairment
• Intracranial bleeding

Adverse effects

• Asthenia
• Gastrointestinal disturbances
• Dry mouth
• Confusion
• Visual impairment
• Hypotension
• Electrolyte imbalances
• Pulmonary edema
• Hemoptysis (with inhalation use)
• Bronchospasm (with inhalation use)

Interactions

• Potassium-sparing diuretics may increase the risk of hyperkalemia
• Other diuretics may have additive effects
• Caution with nephrotoxic agents

Precautions

• Caution in patients with diabetes mellitus
• Caution in the elderly
• Caution in patients with gout
• Caution in patients with hepatic impairment
• Monitor renal function and electrolytes regularly
• May cause blue fluorescence of urine

Pregnancy

Manufacturer advises avoid due to potential toxicity in animal studies.

Breast-feeding

Manufacturer advises avoid due to lack of information available.

Storage

Store in a cool, dry place, away from light. Do not freeze.

Formulations

• Solution for injection
• Inhalation powder
• Oral solution

Indications

• Chronic lymphocytic leukemia
• Non-Hodgkin's lymphoma
• Multiple myeloma

Dosage

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

Adults: Refer to local protocol for specific dosing guidelines.

Mechanism of action

Bendamustine acts as an alkylating agent, resulting in the formation of DNA cross-links which impede DNA replication and transcription. This leads to cell cycle arrest and ultimately triggers apoptosis in rapidly dividing cancer cells. Additionally, it has antimetabolite properties, inhibiting the synthesis of nucleic acids, thus further contributing to its cytotoxic effects.

Pharmacodynamics

The pharmacodynamics of bendamustine involve its dual action on both DNA and RNA synthesis. The drug's ability to induce DNA cross-linking is particularly noteworthy, as it leads to a robust cytotoxic effect in neoplastic cells. Bendamustine also modulates the immune response by affecting the tumor microenvironment, which may enhance its efficacy against certain malignancies.

Pharmacokinetics

Bendamustine is administered via intravenous infusion, and its pharmacokinetics include rapid distribution into tissues with a volume of distribution of approximately 20 L/m². The elimination half-life ranges from 30 to 60 minutes, with metabolites being primarily excreted through the urine. Due to its unique structure, bendamustine does not show significant cross-resistance with other alkylating agents.

Adverse effects

• Gastrointestinal disturbances
• Bone marrow suppression
• Increased risk of infections
• Nausea and vomiting
• Fatigue
• Anemia
• Thrombocytopenia
• Leukopenia

Interactions

• Increased risk of myelosuppression with other myelosuppressive agents
• Potential for increased toxicity with live vaccines
• May interact with anticoagulants

Precautions

• Monitor for signs of infection due to immunosuppression
• Caution in patients with liver impairment
• Avoid in patients with a history of severe hypersensitivity reactions to bendamustine or other alkylating agents
• Patients with known hepatitis B virus infection should be monitored for reactivation

Pregnancy

Bendamustine is not recommended during pregnancy due to potential harm to the fetus. Women of childbearing potential should be advised to use effective contraception.

Breast-feeding

Breastfeeding is not recommended during treatment with bendamustine due to the potential for serious adverse effects in the nursing infant.

Storage

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

Formulations

• Bendamustine hydrochloride injection

Indications

• Multiple myeloma
• Chronic lymphocytic leukemia (CLL)
• Non-Hodgkin lymphoma

Dosage

Children: There is limited data on the use of bendamustine in paediatric patients. Refer to the BNF for Children for specific dosing recommendations.

Adults: The recommended adult dosage for bendamustine varies depending on the specific indication and treatment regimen; refer to the BNF for detailed dosing guidelines.

Mechanism of action

Bendamustine acts as a bifunctional alkylating agent that forms electrophilic alkyl groups, which covalently bond to DNA and other cellular macromolecules. This results in the formation of intra- and inter-strand crosslinks between DNA bases, ultimately leading to apoptosis. The exact molecular mode of action remains poorly understood; however, it has been shown to induce apoptosis in myeloma cell lines by activating specific DNA-damage signaling pathways and causing cell cycle arrest.

Pharmacodynamics

Bendamustine has been studied for its impact on cardiac function, with no significant mean changes in QTc interval greater than 20 milliseconds detected within one hour post-infusion. This suggests that the drug does not pose significant risks for QT prolongation in clinical use.

Pharmacokinetics

Bendamustine is administered intravenously, and its pharmacokinetics are characterized by rapid distribution and elimination. It has a half-life of approximately 30 minutes to 2 hours, depending on individual patient factors. Bendamustine is metabolized in the liver, primarily by cytochrome P450 enzymes, and its metabolites are excreted primarily through the urine.

Adverse effects

• Nausea
• Vomiting
• Myelosuppression
• Fatigue
• Fever
• Infections
• Rash
• Peripheral neuropathy

Precautions

• Use with caution in patients with liver or kidney impairment
• Monitor blood counts regularly due to the risk of myelosuppression
• Avoid use in patients with active infections

Pregnancy

Bendamustine may cause fetal harm. It is not recommended for use during pregnancy.

Breast-feeding

It is not known whether bendamustine is excreted in human milk. Caution should be exercised when administering to a nursing woman.

Storage

Store at room temperature, away from light and moisture. Do not freeze.

Formulations

• Injection, 100 mg/4 mL (single-use vial)

Mechanism of action

Butyl compounds act by interacting with various biological pathways depending on their specific structure. For example, in the context of pharmaceutical use, they may function as solvents for drugs, enhancing solubility and bioavailability, or may have specific receptor interactions based on their functional groups. The precise mechanism of action would vary with the specific butyl derivative.

Pharmacodynamics

The pharmacodynamics of butyl compounds can vary widely. Generally, they may affect various physiological processes depending on their chemical nature. For example, butyl derivatives may exhibit anti-inflammatory, analgesic, or even anesthetic properties in certain contexts. The pharmacodynamic profile is largely dependent on the specific butyl compound and its interactions with cellular receptors and enzymes.

Pharmacokinetics

The pharmacokinetics of butyl compounds vary significantly among different derivatives. Commonly, these compounds are absorbed through various routes, depending on their formulation. They may undergo metabolic processes in the liver before being excreted primarily via urine. The exact absorption rates, half-lives, and clearance rates would depend on the specific butyl derivative and its formulation.

Pregnancy

There are no specific studies regarding the use of butyl compounds in pregnancy. Caution should be exercised.

Breast-feeding

There is limited information on the excretion of butyl compounds in human breast milk. Caution is advised.

Storage

Store in a well-closed container, protected from light and moisture.

Indications

• Major depressive disorder
• Generalized anxiety disorder
• Schizophrenia
• Bipolar disorder
• Obsessive-compulsive disorder

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines, as pediatric dosages are often calculated based on weight and the specific condition being treated.

Adults: Refer to specific prescribing information for individual tertiary drugs, as dosing can vary widely based on the compound and patient characteristics.

Mechanism of action

Tertiary compounds, particularly tertiary amines, often act as antagonists or modulators of neurotransmitter receptors in the central nervous system. They may inhibit reuptake of neurotransmitters like serotonin, norepinephrine, and dopamine, enhancing their availability in the synaptic cleft. This modulation can lead to altered mood, cognition, and perception, which is beneficial in treating conditions such as depression and schizophrenia.

Pharmacodynamics

The pharmacodynamic effects of tertiary compounds can vary widely depending on the specific drug. Generally, they exhibit a range of effects including sedation, anxiolytic activity, and mood elevation. Due to their ability to interact with multiple receptor types, including adrenergic, muscarinic, and histaminergic receptors, they may also produce side effects such as sedation, anticholinergic effects, and weight gain.

Pharmacokinetics

Tertiary compounds are usually well-absorbed following oral administration, with peak plasma concentrations occurring within a few hours. They are extensively metabolized in the liver, primarily through cytochrome P450 enzymes, leading to various active and inactive metabolites. The elimination half-lives can vary, influencing dosing schedules. They are typically excreted in urine, and their pharmacokinetic profiles can be affected by factors such as age, liver function, and potential drug interactions.

Pregnancy

The safety of tertiary medications during pregnancy varies. Consult specific drug references for individual agents.

Breast-feeding

Consult specific drug references for individual agents regarding use during breastfeeding.

Storage

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

Mechanism of action

Ethanol affects the brain’s neurons in several ways. It alters their membranes as well as their ion channels, enzymes, and receptors. Alcohol also binds directly to the receptors for acetylcholine, serotonin, GABA, and the NMDA receptors for glutamate. The sedative effects of ethanol are mediated through binding to GABA receptors and glycine receptors (alpha 1 and alpha 2 subunits). It also inhibits NMDA receptor functioning. In its role as an anti-infective, ethanol acts as an osmolyte or dehydrating agent that disrupts the osmotic balance across cell membranes. ... Ethanol is known to affect a large number of membrane proteins that participate in signaling pathways such as neurotransmitter receptors, enzymes, and ion channels, and there is extensive evidence that ethanol interacts with a variety of neurotransmitters. The major actions of ethanol involve enhancing the inhibitory effects of gamma-aminobutyric acid (GABA) at GABAa receptors and blockade of the N-methyl-D-aspartate (NMDA) subtype of glutamate, an excitatory amine acid (EAA) receptor. Animal studies indicate that the acute effects of ethanol result from competitive inhibition of glycine binding to NMDA receptor and disruption of glutamatergic neurotransmission by inhibiting the response of the NMDA receptor. Persistent glycine antagonism and attenuation of glutamatergic neurotransmission by chronic ethanol exposure results in tolerance to ethanol by enhancing EAA neurotransmission and NMDA receptor upregulation. The latter appears to involve selective increases in NMDA R2B subunit concentrations and other molecular changes in specific brain loci. The abrupt withdrawal of ethanol thus produces a hyperexcitable state that leads to the ethanol withdrawal syndrome and excitotoxic neuronal death. GABA-mediated inhibition, which normally acts to limit excitation, is eliminated during ethanol withdrawal syndrome and further intensifies this excitation. In addition, NMDA receptors function to inhibit the release of dopamine in the nucleus accumbens and mesolimbic structures, which modulate the reinforcing action of addictive xenobiotics such as ethanol. By inhibiting NMDA receptor activity, ethanol could increase dopamine release from the nucleus accumbens and ventral tegmental area and could thus create dependence. Chronic ethanol administration also results in tolerance, dependence, and an ethanol withdrawal syndrome, mediated, in part, by desensitization and or downregulation of GABAa receptors. The development of alcoholic ketoacidosis (AKA) requires that a combination of physical and physiologic events occur. The normal response to starvation and depletion of hepatic glycogen stores is for amino acids to be converted to pyruvate. Pyruvate can serve as a substrate for gluconeogenesis, be converted to acetyl-CoA, which can enter the Krebs cycle or can be utilized in various biosynthetic pathways (eg, fatty acid, ketone bodies, cholesterol, and acetylcholine) ... Ethanol metabolism generates NADH, resulting in an excess of reducing potential. This high redox state favors the conversion of pyruvate to lactate, diverting pyruvate from being a substrate for gluconeogenesis. To compensate for the lack of normal metabolic substrates, the body mobilizes fat from adipose tissue and increased fatty acid metabolism as an alternative source of energy. This response is mediated by a decrease in insulin and an increased secretion of glucagon, catecholamines, growth hormone, and cortisol. Fatty acid metabolism results in the formation of acetyl-CoA and it combines with the excess acetate that is generated from ethanol metabolism to form acetoacetate. Most of the acetoacetate is reduced to beta-hydroxybutyrate due to the excess reducing potential or high redox state of the cell. Volume depletion interferes with the renal elimination of acetoacetate and beta-hydroxybutyrate, and contributes to the acidosis. An elevated lactate concentration may result from shunting from pyruvate or

Pharmacodynamics

Alcohol produces injury to cells by dehydration and precipitation of the cytoplasm or protoplasm. This accounts for its bacteriocidal and antifungal action. When alcohol is injected in close proximity to nerve tissues, it produces neuritis and nerve degeneration (neurolysis). Ninety to 98% of ethanol that enters the body is completely oxidized. Ethanol is also used as a cosolvent to dissolve many insoluble drugs and to serve as a mild sedative in some medicinal formulations. Ethanol also binds to GABA, glycine, NMDA receptors and modulates their effects. Ethanol is also metabolised by the hepatic enzyme alcohol dehydrogenase.

Mechanism of action

Mannitol is an osmotic diuretic that is metabolically inert in humans and occurs naturally, as a sugar or sugar alcohol, in fruits and vegetables. Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma. As a result, cerebral edema, elevated intracranial pressure, and cerebrospinal fluid volume and pressure may be reduced. As a diurectic mannitol induces diuresis because it is not reabsorbed in the renal tubule, thereby increasing the osmolality of the glomerular filtrate, facilitating excretion of water, and inhibiting the renal tubular reabsorption of sodium, chloride, and other solutes. Mannitol promotes the urinary excretion of toxic materials and protects against nephrotoxicity by preventing the concentration of toxic substances in the tubular fluid. As an Antiglaucoma agent mannitol levates blood plasma osmolarity, resulting in enhanced flow of water from the eye into plasma and a consequent reduction in intraocular pressure. As a renal function diagnostic aid mannitol is freely filtered by the glomeruli with less than 10% tubular reabsorption. Therefore, its urinary excretion rate may serve as a measurement of glomerular filtration rate (GFR). The exact mechanism of action of inhaled mannitol in the symptomatic maintenance treatment of cystic fibrosis remains unclear. It is hypothesized that mannitol produces an osmotic gradient across the airway epithelium that draws fluid into the extracellular space and alters the properties of the airway surface mucus layer, allowing easier mucociliary clearance. MANNITOL IS.../USED/ IN PROPHYLAXIS OF ACUTE RENAL FAILURE. IT IS USED FOR THIS PURPOSE IN CONDITIONS AS DIVERSE AS CARDIOVASCULAR OPERATIONS, SEVERE TRAUMATIC INJURY, OPERATIONS IN THE PRESENCE OF SEVERE JAUNDICE, AND MGMNT OF HEMOLYTIC TRANSFUSION REACTIONS. IN EACH OF THESE CONDITIONS, A PRECIPITOUS FALL IN THE FLOW OF URINE MAY BE ANTICIPATED EITHER AS THE RESULT OF AN ACUTELY REDUCED FILTRATION RATE OR FROM ACUTE CHANGES IN TUBULAR PERMEABILITY. THE LATTER MAY BE CONSEQUENCE OF THE PRESENCE OF NOXIOUS AGENT WITHIN THE TUBULAR FLUID IN EXCESSIVELY HIGH CONCN, IN SOME INSTANCES SUFFICIENT TO RESULT IN ACTUAL PRECIPITATION. IN THESE SITUATIONS, MANNITOL EXERTS OSMOTIC EFFECT WITHIN THE TUBULAR FLUID, INHIBITS WATER REABSORPTION, & MAINTAINS THE RATE OF URINE FLOW. ...CONCN OF TOXIC AGENT WITHIN TUBULAR FLUID DOES NOT REACH EXCESSIVELY HIGH LEVELS THAT OTHERWISE WOULD HAVE BEEN ACHIEVED BY MORE COMPLETE REABSORPTION OF WATER. ...EVEN THOUGH /GLOMERULAR/ FILTRATION RATE IS REDUCED, MANNITOL IS STILL FILTERED @ GLOMERULUS. THE TUBULAR IMPERMEABILITY TO MANNITOL IS NOT ALTERED BY ACUTE RENAL ISCHEMIA OF SHORT DURATION. HENCE, THE MANNITOL THAT IS FILTERED IS ALSO EXCRETED IN THE VOIDED URINE. UNREABSORBED SOLUTE LIMITS BACK DIFFUSION OF WATER. ...URINE VOL CAN BE MAINTAINED EVEN IN PRESENCE OF DECR GLOMERULAR FILTRATION.

Pharmacodynamics

Chemically, mannitol is an alcohol and a sugar, or a polyol; it is similar to xylitol or sorbitol. However, mannitol has a tendency to lose a hydrogen ion in aqueous solutions, which causes the solution to become acidic. For this reason, it is not uncommon to add a substance to adjust its pH, such as sodium bicarbonate. Mannitol is commonly used to increase urine production (diuretic). It is also used to treat or prevent medical conditions that are caused by an increase in body fluids/water (e.g., cerebral edema, glaucoma, kidney failure). Mannitol is frequently given along with other diuretics (e.g., furosemide, chlorothiazide) and/or IV fluid replacement. Inhaled mannitol has the possibility to cause bronchospasm and hemoptysis; the occurrence of either should lead to discontinuation of inhaled mannitol.

Mechanism of action

Bendamustine is a bifunctional mechlorethamine derivative capable of forming electrophilic alkyl groups that covalently bond to other molecules. Through this function as an alkylating agent, bendamustine causes intra- and inter-strand crosslinks between DNA bases resulting in cell death. It is active against both active and quiescent cells, although the exact mechanism of action is unknown. Multiple myeloma is a fatal hematological disease caused by malignant transformation of plasma cells. Bendamustine has been proven to be a potent alternative to melphalan in phase 3 studies, yet its molecular mode of action is still poorly understood. The four-myeloma cell lines NCI-H929, OPM-2, RPMI-8226, and U266 were cultured in vitro. Apoptosis was measured by flow cytometry after annexin V FITC and propidium iodide staining. Cell cycle distribution of cells was determined by DNA staining with propidium iodide. Intracellular levels of (phosphorylated) proteins were determined by western blot. /It was shown/ that bendamustine induces apoptosis with an IC50 of 35-65 mug/ml and with cleavage of caspase 3. Incubation with 10-30 mug/ml results in G2 cell cycle arrest in all four-cell lines. The primary DNA-damage signaling kinases ATM and Chk2, but not ATR and Chk1, are activated. The Chk2 substrate Cdc25A phosphatase is degraded and Cdc2 is inhibited by inhibitory phosphorylation of Tyr15 accompanied by increased cyclin B levels. Additionally, p53 activation occurs as phosphorylation of Ser15, the phosphorylation site for ATM. p53 promotes Cdc2 inhibition by upregulation of p21. Targeting of p38 MAPK by the selective inhibitor SB202190 significantly increases bendamustine induced apoptosis. Additionally, SB202190 completely abrogates G2 cell cycle arrest. Bendamustine induces ATM-Chk2-Cdc2-mediated G2 arrest and p53 mediated apoptosis. Inhibition of p38 MAPK augments apoptosis and abrogates G2 arrest and can be considered as a new therapeutic strategy in combination with bendamustine. Microarray-based gene expression profiling, real-time PCR, immunoblot, cell cycle, and functional DNA damage repair analyses were used to characterize response to bendamustine and compare it with chlorambucil and phosphoramide mustard. Bendamustine displays a distinct pattern of activity unrelated to other DNA-alkylating agents. Its mechanisms of action include activation of DNA-damage stress response and apoptosis, inhibition of mitotic checkpoints, and induction of mitotic catastrophe. In addition, unlike other alkylators, bendamustine activates a base excision DNA repair pathway rather than an alkyltransferase DNA repair mechanism. These results suggest that bendamustine possesses mechanistic features that differentiate it from other alkylating agents and may contribute to its distinct clinical efficacy profile. Bendamustine is a bifunctional mechlorethamine derivative containing a purine-like benzimidazole ring. Mechlorethamine and its derivatives form electrophilic alkyl groups. These groups form covalent bonds with electron-rich nucleophilic moieties, resulting in interstrand DNA crosslinks. The bifunctional covalent linkage can lead to cell death via several pathways. Bendamustine is active against both quiescent and dividing cells. The exact mechanism of action of bendamustine remains unknown.

Pharmacodynamics

No mean changes in QTc interval greater than 20 milliseconds were detected up to one hour post-infusion.