PT
● MODULE 01 / 20
General Pharmacology & Drug Development
Start with drug names, dosage forms, routes and the evidence needed to use medicines responsibly.
Quick revision ↓ Medical Dictionary
FULL CHAPTER EXPLANATION
Deep Learning — Module 01
Read this section in sequence. It moves from drug targets to therapeutic effects, adverse reactions and safe use.
01
What a medicine contains
A drug changes a biological process; a medicine combines an active ingredient with a formulation suitable for administration. Generic names identify the substance, whereas brand names identify marketed products. Strength, total amount, concentration and dose describe different things. A 250 mg tablet contains a stated amount per tablet; a liquid labelled 250 mg/5 mL needs a volume calculation before administration. Excipients and release characteristics can matter clinically.
02
Routes and dosage forms
Oral treatment is convenient but absorption and first-pass metabolism can limit exposure. Intravenous administration enters systemic circulation directly and cannot be retrieved once given. Intramuscular and subcutaneous absorption depend partly on perfusion. Inhaled, topical and ocular routes can target a site but still cause systemic adverse effects. Sublingual absorption bypasses much initial hepatic first-pass metabolism. Modified-release and enteric-coated products should not be crushed without checking the formulation.
03
From discovery to evidence
Preclinical work investigates pharmacology and toxicity before human studies. Phase I commonly examines tolerability and pharmacokinetics; phase II explores efficacy and dose; phase III compares benefit and harm in larger populations; post-marketing surveillance detects uncommon or delayed problems. These categories describe typical purposes, not an inflexible sequence. Randomization reduces confounding, blinding reduces measurement and performance bias, and clinically meaningful outcomes matter more than a favorable surrogate alone.
04
Reading a treatment claim
Relative risk reduction can look impressive when baseline risk is low. If event risk falls from 10% to 8%, absolute risk reduction is 2 percentage points and the number needed to treat is 50 over that study period. Compare confidence intervals, harms, population and follow-up. Statistical significance does not guarantee a worthwhile benefit for an individual. A medicine approved for one indication is not automatically effective for every related symptom.
05
Practical calculation and communication
For a teaching prescription of 500 mg from a liquid containing 250 mg/5 mL, required volume is 500 divided by 50 mg/mL, or 10 mL. Carry units through every step, independently check high-risk calculations, and use an appropriate measuring device. A medication history includes nonprescription products, supplements, allergies and the actual way medicines are taken. Explain the purpose, expected benefit, administration and important warning symptoms in language the patient understands.
High-Yield Revision
- Generic name, strength, formulation and route must all match the intended medicine.
- Absolute benefit depends on baseline risk and follow-up duration.
- Local administration does not guarantee absence of systemic effects.
Common Exam & Concept Pitfalls
- Do not equate a drug concentration with the dose administered.
- Do not crush modified-release formulations by default.
Sources & Further Reading
Curriculum scope checked 23 September 2026. These original study notes summarize established principles; current institutional guidance and product information govern clinical use. Faculty review is pending.
RAHBAR study structure: target → drug action → therapeutic use → adverse effects → monitoring. Use institutional curriculum and faculty guidance for local sequencing, practical requirements and assessment specifications.