B Pharmacy

Cotrimoxazole (Trimethoprim + Sulfamethoxazole) Cotrimoxazole is a combination antibiotic containing sulfamethoxazole and trimethoprim. Mechanism of Action Sulfamethoxazole: Inhibits dihydropteroate synthase, blocking folic acid synthesis → inhibits DNA/RNA production. Trimethoprim: Inhibits dihydrofolate reductase, further blocking folic acid formation. Combined effect: Sequential blockade of folic acid synthesis enhances antibacterial activity. Pharmacokinetics Absorption: Rapid and complete via GI … Read more

Definition of Sulfonamides (Sulfa Drugs) Sulfonamides are synthetic antimicrobial agents used to treat bacterial infections. Available in oral and topical forms (tablets, creams, solutions). Mechanism of Action They inhibit dihydropteroate synthase, an enzyme involved in folic acid synthesis, essential for bacterial DNA/RNA production — resulting in a bacteriostatic effect. Classification of Sulfonamides Sulfonamides, or sulfa … Read more

General Principles of Chemotherapy explain selective toxicity, drug resistance, and combination therapy in treating infections and cancer. General Principles of Chemotherapy Chemotherapy in pharmacology refers to the use of chemical agents to destroy or inhibit the growth of infectious organisms or cancer cells. In the context of antimicrobial chemotherapy, it primarily targets bacteria, viruses, fungi, … Read more

Antiemetics are drugs that prevent or control nausea and vomiting by acting on central or peripheral pathways. Definition of Antiemetics Drugs used to prevent or control nausea and vomiting due to various causes (motion sickness, chemotherapy, infections, etc.) Classes of Antiemetic Drugs Dopamine (D₂) Receptor Antagonists Examples: Metoclopramide, Domperidone Mechanism: Block D₂ receptors in CTZ … Read more

Definition of Emetics Drugs that induce vomiting by stimulating the vomiting center or CTZ. Indications Rarely used today Used only in specific poisoning cases when gastric lavage is not possible (and patient is conscious) Classes of Emetics Central Acting Example: Apomorphine Mechanism: Stimulates CTZ (dopamine agonist) Use: Induce vomiting in poisoning (rarely used now) Caution: … Read more

Definition of Vomiting It is the forceful expulsion of stomach contents through the mouth. It is a protective reflex triggered by various stimuli and coordinated by the emetic center in the brainstem. Common Causes Gastrointestinal irritation (e.g., food poisoning, infection) Motion sickness Pregnancy (morning sickness) Migraines Medications (e.g., chemotherapy, opioids) Psychological factors (e.g., stress, anxiety) … Read more

Definition of Carminatives Carminatives are agents that help in the expulsion of gas from the stomach or intestines and relieve flatulence and abdominal bloating. Mechanism of Action Relax gastrointestinal smooth muscles Reduce surface tension of gas bubbles Help expel gas from GIT Some have mild antiseptic or antispasmodic properties Common Carminative Agents Herbal Oils (Essential … Read more

Definition of Digestants These are agents that aid the process of digestion by supplementing endogenous digestive enzymes or acids. Indications Indigestion (dyspepsia) Pancreatic insufficiency Hypochlorhydria (low stomach acid) Chronic illness or post-operative GI dysfunction Classes of Digestants Enzyme Preparations Examples: Fungal diastase + Pepsin combinations (common in OTC tonics) Pancreatin (contains amylase, lipase, protease) Mechanism: … Read more

Appetite Suppressants (Anorexiants) Appetite Suppressants (Anorexiants) are drugs that reduce hunger by acting on central appetite control centers. Indications Obesity Overeating disorders Metabolic syndrome (adjunct to diet & exercise) Classes of Appetite Suppressants Sympathomimetic Agents (Stimulants) Examples: Phentermine, Diethylpropion Mechanism: Increase norepinephrine and dopamine → CNS stimulation → reduced hunger Use: Short-term obesity treatment Side … Read more

Appetite Stimulants (Orexiants) Appetite Stimulants (Orexiants) are drugs that increase hunger and food intake by acting on central appetite-regulating pathways. Indications Anorexia Cancer cachexia HIV/AIDS-associated wasting Depression-related weight loss Geriatric undernutrition Classes of Appetite Stimulants Antihistamines (H1 blockers) Examples: Cyproheptadine Mechanism: H1 receptor antagonism + 5-HT2 receptor blockade → ↑ appetite Use: Pediatric and geriatric … Read more