M.S.A

Indications

• Topical antiseptic for minor wounds
• Treatment of infections caused by bacteria and protozoa
• Antiseptic in surgical procedures

Dosage

Children: The dosage should be determined based on the clinical context and the specific formulation used. Refer to the BNF for Children for detailed dosing recommendations.

Adults: The dosage should be determined based on the clinical context and the specific formulation used. Refer to the BNF for detailed dosing recommendations.

Mechanism of action

Acriflavine exerts its antimicrobial effects primarily through intercalation into DNA, which inhibits nucleic acid synthesis. This mechanism disrupts the replication of bacterial cells and may also affect protozoal organisms, thereby contributing to its therapeutic effects.

Pharmacodynamics

Acriflavine displays bactericidal activity against a range of gram-positive and gram-negative bacteria. It is also effective against certain protozoa, making it useful in treating infections caused by these organisms. The drug's efficacy is influenced by concentration and exposure time, with higher concentrations generally leading to increased antimicrobial activity.

Pharmacokinetics

Acriflavine is poorly absorbed when administered orally, leading to minimal systemic exposure. However, when applied topically, it can exert local effects at the site of application. The elimination half-life and detailed metabolic pathways of acriflavine are not well characterized in the available literature, and further studies may be required to elucidate these aspects.

Contra-indications

• Hypersensitivity to acriflavine or any of its components
• Severe renal impairment

Adverse effects

• Local irritation at the application site
• Allergic reactions including rash and pruritus
• Nausea and vomiting
• Discoloration of the urine

Interactions

• Caution is advised when used with other antiseptics or topical agents
• May interfere with certain laboratory tests due to its coloring properties

Precautions

• Avoid contact with eyes and mucous membranes
• Use with caution in patients with liver impairment
• Monitor for signs of hypersensitivity reactions

Pregnancy

Acriflavine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus, as adequate studies in pregnant women are not available.

Breast-feeding

Acriflavine is excreted in breast milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Topical solution
• Cream
• Ointment

Indications

• Minor cuts
• Abrasions
• First aid antiseptic

Dosage

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

Adults: Apply mercurochrome topically to the affected area as needed for antiseptic purposes.

Mechanism of action

Mercurochrome exhibits antiseptic properties, primarily through its ability to disrupt microbial cell membranes and inhibit bacterial growth. The mercury component in its structure contributes to its antimicrobial activity by binding to thiol groups in proteins, leading to denaturation and inactivation of microbial proteins.

Pharmacodynamics

The pharmacodynamic profile of mercurochrome indicates that it is effective against a variety of microorganisms, including gram-positive and some gram-negative bacteria. Its antimicrobial efficacy is influenced by concentration, contact time, and the presence of organic matter. However, its safety profile has raised concerns, especially regarding potential systemic absorption of mercury, leading to limitations in its clinical use.

Pharmacokinetics

Mercurochrome is primarily used topically, and its absorption through intact skin is minimal. However, it may be absorbed systemically in cases of extensive application or through broken skin. The compound is metabolized in the body, and mercury can lead to accumulation and toxicity. It is important to monitor for any signs of mercury poisoning when used, especially in sensitive populations such as children and pregnant women.

Pregnancy

There is limited information on the safety of mercurochrome during pregnancy. It should only be used if the benefits outweigh the risks, as the potential for mercury exposure may pose risks to the fetus.

Breast-feeding

Due to the potential for mercury exposure, caution is advised when using mercurochrome during breastfeeding. It is recommended to consult a healthcare professional before use.

Storage

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

Mechanism of action

Oxides do not have a single mechanism of action as they are a broad category of compounds. However, in general, metal oxides can exhibit catalytic properties, while non-metal oxides may participate in biochemical reactions by forming acids or bases upon dissolution in water.

Pharmacodynamics

The pharmacodynamics of oxides depend on the specific type of oxide and its interaction with biological systems. For instance, metal oxides may have antimicrobial properties, while certain non-metal oxides can influence metabolic pathways through their acid-base chemistry. The effects vary widely, necessitating specific studies for each oxide's role in therapeutic contexts.

Pharmacokinetics

The pharmacokinetics of oxides are also variable. Many metal oxides are poorly soluble and thus have limited absorption when ingested. Non-metal oxides, such as carbon dioxide, can be readily absorbed and utilized in metabolic processes. The distribution, metabolism, and excretion of oxides depend on their chemical form and the biological system in which they are involved.

Pregnancy

Not applicable as oxide is not a drug but a class of chemical compounds.

Breast-feeding

Not applicable as oxide is not a drug but a class of chemical compounds.

Storage

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

Indications

• Bacterial infections
• Urinary tract infections
• Respiratory tract infections
• Gastrointestinal infections
• Certain skin infections

Dosage

Children: Paediatric dosing of sulphanilamide must be referenced from the BNF for Children, as specific doses vary by age and weight.

Adults: For adults, the dosage of sulphanilamide should be determined based on the specific condition being treated. Refer to the BNF for exact dosing guidelines.

Mechanism of action

Sulphanilamide acts as a competitive inhibitor of the bacterial enzyme dihydropteroate synthetase. By mimicking para-aminobenzoic acid (PABA), it prevents the enzyme from synthesizing folic acid, which is essential for bacterial growth and replication. This inhibition of folic acid metabolism effectively stunts bacterial proliferation.

Pharmacodynamics

As a sulfonamide antibiotic, sulphanilamide exhibits bacteriostatic properties, inhibiting the growth of bacteria by blocking the incorporation of PABA into folic acid. Its activity is dependent on the bacterial sensitivity, which is consistent across sulfonamide derivatives. Resistance to one sulfonamide typically indicates resistance to others within the class. The drug is well-absorbed when administered orally, although parenteral forms can cause irritation due to their alkaline nature.

Pharmacokinetics

Sulphanilamide is absorbed well from the gastrointestinal tract, achieving high tissue distribution including pleural, peritoneal, synovial, and ocular fluids. Although its penetration into cerebrospinal fluid is significant, it is not commonly used for meningitis treatment. The drug's antibacterial effectiveness may be diminished in the presence of pus, which can inhibit its action.

Adverse effects

• Allergic reactions (e.g., skin rash, pruritus)
• Gastrointestinal disturbances (e.g., nausea, vomiting)
• Hematologic reactions (e.g., leukopenia, thrombocytopenia)
• Renal toxicity (e.g., crystalluria, nephritis)
• Hepatotoxicity (rare)

Interactions

• May enhance the effects of anticoagulants (e.g., warfarin)
• May decrease the efficacy of oral contraceptives
• Potential interaction with methotrexate, increasing toxicity
• Increased risk of adverse effects with other nephrotoxic agents

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of hypersensitivity reactions
• Consider alternative therapy in patients with G6PD deficiency
• Ensure adequate hydration to prevent crystalluria

Pregnancy

Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Category C.

Breast-feeding

Sulfanilamide is excreted in breast milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Tablets
• Oral suspension
• Injectable formulations

Mechanism of action

Sulfanilamide is a competitive inhibitor of bacterial enzyme dihydropteroate synthetase. This enzyme normally uses para-aminobenzoic acid (PABA) for synthesizing the necessary folic acid. The inhibited reaction is normally necessary in these organisms for the synthesis of folic acid. Without it, bacteria cannot replicate. Sulfonamides are structural analogs and competitive antagonist of para-aminobenzoic acid ... and thus prevent normal bacterial utilization of para-aminobenzoic acid for the synthesis of folic acid (pteroylglutamic acid). ... More specifically, sulfonamides are competitive inhibitors of dihydropteroate synthase, the bacterial enzyme responsible for the incorporation of para-aminobenzoic acid into dihydropteroic acid, the immediate precursor of folic acid. /Sulfonamides/

Pharmacodynamics

Sulfanilamide is a sulfonamide antibiotic. The sulfonamides are synthetic bacteriostatic antibiotics with a wide spectrum against most gram-positive and many gram-negative organisms. However, many strains of an individual species may be resistant. Sulfonamides inhibit multiplication of bacteria by acting as competitive inhibitors of <i>p</i>-aminobenzoic acid in the folic acid metabolism cycle. Bacterial sensitivity is the same for the various sulfonamides, and resistance to one sulfonamide indicates resistance to all. Most sulfonamides are readily absorbed orally. However, parenteral administration is difficult, since the soluble sulfonamide salts are highly alkaline and irritating to the tissues. The sulfonamides are widely distributed throughout all tissues. High levels are achieved in pleural, peritoneal, synovial, and ocular fluids. Although these drugs are no longer used to treat meningitis, CSF levels are high in meningeal infections. Their antibacterial action is inhibited by pus.