Unit 23: Pharmacology — Short Questions

The drug developmental process has five stages: (1) Preclinical Research — compounds are tested in vitro (cell culture) and in vivo (animals) for safety, toxicity and efficacy; (2) Clinical Trials — Phase 1 tests 20–100 healthy volunteers for safety and dosage, Phase 2 tests 100–300 patients for effectiveness and side effects, and Phase 3 tests 1,000–3,000 patients to confirm efficacy and monitor adverse reactions; (3) FDA Drug Review — regulatory agencies (FDA/EMA) examine all trial data to approve or reject the drug; (4) Manufacturing and Marketing — the approved drug is produced on a large scale and made available for medical use; (5) Post-Marketing Surveillance — the drug is continuously monitored after release for long-term and rare side effects.

Common side effects of penicillin include nausea, vomiting, diarrhea, abdominal pain, and skin rashes.

Tetracycline enters bacterial cells and reversibly binds to the 30S ribosomal subunit. By binding here, it prevents aminoacyl-tRNA from attaching to the acceptor site of the ribosome, thereby blocking translation and protein synthesis. This makes tetracycline a bacteriostatic drug (it stops bacterial growth and multiplication rather than killing the bacteria outright).

Antiviral drugs are used to treat a wide range of viral infections in general, preventing the growth and multiplication of viruses such as those causing hepatitis, influenza, and herpes. Antiretroviral drugs are a specific type of antiviral drug designed to treat illnesses caused by retroviruses, such as HIV; they help the immune system defend itself and stop HIV from proliferating by acting on the reverse transcriptase enzyme that retroviruses use to replicate using their RNA genome. Thus, all antiretrovirals are antivirals, but not all antivirals are antiretrovirals.

Monoclonal antibodies have the following advantages: (i) lower toxicity and potential for long-lasting effects compared to traditional drugs; (ii) fewer side effects compared to conventional chemotherapeutics; (iii) high specificity, binding to a single target with minimal variability; (iv) targeted therapy in cancer that reduces damage to healthy tissues; (v) they are easy to prepare and can be used for research purposes; and (vi) they reduce the risk of drug interactions. They are also central to personalized medicine, enabling treatment tailored to each patient's biology.