Pharmacology
Endocrine and metabolic drugs
Endocrine medicines are grouped here by the hormonal axis or metabolic pathway they act on, because that is what predicts their monitoring, their interactions and the consequences of stopping them abruptly. Many replace or oppose a hormone the body already makes, which is why both excess and deficiency states appear as adverse effects.
10 classes across 5 mechanism families.
1. Sex hormones and reproductive agents
These agents supply, oppose or modulate oestrogen, progestogen and androgen signalling. Thrombotic risk, hepatic enzyme interactions and hormone-sensitive cancer dominate their safety profile.
- Sex hormones and hormonal contraceptives — Oestrogens, progestogens and androgens; thrombotic risk and enzyme-inducer interactions are the key safety points.
2. Glucose-lowering agents
These medicines lower blood glucose by increasing insulin supply, improving insulin sensitivity, slowing carbohydrate absorption or promoting urinary glucose loss. Hypoglycaemia risk follows the mechanism, not the potency.
- Biguanides — Metformin and relatives; lactic acidosis and renal thresholds define their cautions.
- Sulfonylureas — Insulin secretagogues; hypoglycaemia and weight gain are the class effects.
- SGLT2 inhibitors — Promote urinary glucose loss; euglycaemic ketoacidosis and genital infection are characteristic.
- GLP-1 receptor agonists — Incretin mimetics with weight loss and gastrointestinal effects; thyroid C-cell warnings apply.
- DPP-4 inhibitors — Prolong endogenous incretin action; generally weight-neutral with a low hypoglycaemia risk.
- Insulins — Replacement therapy classified by onset and duration; hypoglycaemia is the dose-limiting effect.
3. Bone and mineral agents
These medicines act on bone turnover and on calcium and phosphate handling, and are used where fracture risk or mineral homeostasis is the clinical problem.
- Bisphosphonates and bone agents — Reduce osteoclastic resorption; osteonecrosis of the jaw and atypical femoral fracture are the notable risks.
4. Corticosteroids and adrenal agents
These agents act at the glucocorticoid or mineralocorticoid receptor, or on adrenal steroid synthesis. Duration of exposure, rather than dose alone, governs most of their harm.
- Systemic corticosteroids — Broad anti-inflammatory action; adrenal suppression and the hazard of abrupt withdrawal dominate.
5. Thyroid and antithyroid agents
These medicines replace thyroid hormone or suppress its synthesis, and are monitored biochemically rather than symptomatically.
- Thyroid and antithyroid agents — Levothyroxine and the thionamides; agranulocytosis is the antithyroid class warning.
Studying this the efficient way
Learn the mechanism family first, then the classes inside it. Almost every exam question about spectrum, adverse effects or resistance is really a question about which mechanism a drug belongs to. Each class page ends with a 60-second revision block and the traps students most often fall for.