Fertility, STIs & Special Topics

Ovulation Induction and Assisted Reproduction

Almost every fertility drug is really a message sent to one circuit — the hypothalamic–pituitary–gonadal (HPG) axis, the same feedback loop the Endocrine section builds from scratch. Nudge it gently and a single egg ripens where none did before. Push it hard and dozens of follicles swell at once, growing ovaries the size of oranges and leaking fluid into the belly. This is a chapter where the pharmacology is elegant and the reward is a pregnancy — but where the same drugs that create life carry one of medicine's most striking iatrogenic emergencies. Learn the axis, and you learn both.

Sexually Transmitted Infections: A Treatment Map

Treating a sexually transmitted infection is never just about one patient. Every prescription carries three questions at once: which organism, which drug still works, and who else needs treating. The pharmacology is mostly a matter of matching a known bug to a first-line antibiotic — but layered on top is a public-health logic that has no parallel elsewhere in medicine: you treat before the swab comes back, you treat the partner you never met, and you watch, with gonorrhoea, an organism burning through the last drugs we have. This chapter is the map: organism by organism, the drug that still works.

Prostatitis, Pelvic Pain and Interstitial Cystitis

Few complaints frustrate a clinician like the man with chronic pelvic pain who has had five courses of antibiotics and is no better — or the woman whose bladder burns despite every urine culture coming back sterile. These syndromes look like infection, so they get treated like infection, again and again, to no avail. The real pharmacology here is more interesting and more disciplined: know when a bug is truly present and choose an antibiotic that can actually reach the prostate; and know when there is no bug at all, and reach instead for the drugs of neuropathic pain. Getting that distinction right is the whole game.

Prescribing in Pregnancy and Breastfeeding: The Principles and the Blacklist

The instinct of the anxious prescriber is to stop everything the moment two lines appear on a pregnancy test. It feels safe. It is often the most dangerous thing you can do. An uncontrolled seizure, an asthma attack starved of a preventer, an untreated infection, a blood pressure left to climb — these harm two patients, not one. Good prescribing in pregnancy is never about reflexive avoidance. It is about weighing the risk of the illness against the risk of the drug, choosing the best-evidenced agent, and knowing by heart the short list of drugs that truly must not be given.

Drugs and the Kidney: Nephrotoxins and Dosing in Renal Impairment

The kidney is where most drugs come to be measured, thinned out, and thrown away. That makes it uniquely exposed: it receives a fifth of the cardiac output, concentrates whatever it filters, and pays the price for the toxins passing through. So the relationship runs both ways. Some drugs injure the kidney — bluntly, by strangling its blood supply, poisoning its tubules, or crystallising inside them. And a failing kidney injures the patient back, by letting renally cleared drugs pile up to toxic levels. Good prescribing means knowing both directions: which agents are nephrotoxic, and how to dose everything else when the kidney can no longer keep up.