Pre-clinical medicine
Pharmacology
Pharmacology is the science of how medicines work, how the body handles them, and why they cause side effects and interactions. It is the direct foundation for psychiatric prescribing, one of a psychiatrist's core daily tasks.
Depth by stage, Pre-U → Consultant (details)
What is it?
Pharmacology has two halves. Pharmacodynamics is what a drug does to the body (which receptors it acts on, its effects). Pharmacokinetics is what the body does to the drug (absorption, distribution, metabolism and excretion).
Medical students learn major drug classes for each body system, including the nervous system: sedatives, antidepressants, antipsychotics, anticonvulsants and pain medicines, alongside antibiotics, heart drugs and many others.
Safe prescribing, adverse drug reactions, drug interactions and special groups (children, the elderly, pregnancy, kidney or liver disease) are emphasised throughout.
Why does a psychiatrist need it?
Most psychiatric patients receive medication. A psychiatrist must choose the right drug and dose, anticipate side effects such as weight gain or heart rhythm changes, avoid dangerous interactions (for example serotonin syndrome) and adjust for pregnancy, age and other illnesses. Medical school pharmacology is the base on which specialist psychopharmacology is built.
What level is expected at each stage?
Scale: 1. Aware → 2. Understands → 3. Applies → 4. Masters / Teaches. What the levels mean.
- Pre-UNot expected
- Pre-clinicalUnderstandsUnderstands principles of drug action and the main drug classes.
- ClinicalUnderstandsUnderstands how drugs are chosen for common conditions; begins writing practice prescriptions.
- HousemanshipAppliesApplies prescribing under supervision: charts, doses, allergies, interactions.
- Medical officerAppliesApplies independent prescribing for common conditions, including psychiatric medicines in a psychiatry posting.
- Psych traineeAppliesApplies detailed knowledge of psychotropic drugs; pharmacology is a large part of basic sciences exams.
- Specialist / consultantMasters / TeachesMasters complex prescribing: treatment resistance, polypharmacy, pregnancy, and advises colleagues.
What are the key topics?
General principles
- Receptors, agonists, antagonists and partial agonists
- Dose-response curves, potency and efficacy
- Therapeutic index
- Tolerance and dependence
Pharmacokinetics
- Absorption and bioavailability
- Distribution, protein binding and the blood-brain barrier
- Metabolism by liver enzymes (cytochrome P450)
- Excretion and half-life; steady state
- Therapeutic drug monitoring (for example lithium, some anticonvulsants)
Drugs acting on the nervous system
- Autonomic drugs
- Benzodiazepines and other sedatives
- Antidepressants (introductory)
- Antipsychotics (introductory)
- Anticonvulsants and opioids
Safety
- Adverse drug reactions and how to report them
- Drug interactions
- Prescribing in pregnancy, breastfeeding, children and older people
- Prescribing in kidney and liver impairment
- Poisoning and overdose (introduction)
Prescribing practice
- Writing a safe prescription
- Generic names and the Malaysian drug formulary context
- Rational use of medicines and cost
How is it learned and assessed?
- Lectures, PBL and prescribing exercises
- MCQ, short-answer and data-interpretation papers
- Prescribing stations in OSCEs during clinical years
- Psychopharmacology is examined heavily in MMed Psychiatry and MRCPsych Paper A
Typical textbooks and resources
- Rang and Dale's Pharmacology — Elsevier
- Basic and Clinical Pharmacology — Katzung (McGraw Hill)
- Lippincott Illustrated Reviews: Pharmacology — Wolters Kluwer
- British National Formulary (BNF) — widely used reference
- Medical Pharmacology at a Glance — Wiley-Blackwell
Titles are widely used examples; editions change. Use university libraries or legitimate purchases.
Common questions
Is pharmacology the same as psychopharmacology?
Psychopharmacology is the branch of pharmacology focused on medicines that affect the mind and brain. Medical school pharmacology covers all drugs; psychiatrists then study psychiatric drugs in much more depth during specialist training.
When does a doctor start prescribing?
Students practise prescribing in training, but real prescriptions begin in housemanship, under supervision. Medical officers prescribe independently for common conditions.