Doxycycline

Doxycycline is a tetracycline antibiotic medicine available in Bangladesh under many brand names. Below are its uses, side effects and precautions — and every brand with its current price.

• Respiratory tract infections (bronchitis, atypical pneumonia)
• Acne and rosacea
• Skin and soft-tissue infections
• Chlamydia and other sexually transmitted infections
• Cholera, typhus, and other rickettsial infections
• Malaria prophylaxis and leptospirosis (as advised by a doctor)

Common side effects include nausea, stomach upset, diarrhoea, and headache. Doxycycline often causes photosensitivity — the skin burns more easily in sunlight, which matters in Bangladesh's strong sun. Irritation or ulceration of the food pipe can occur if the tablet is taken without enough water or while lying down. Less common effects include oral or vaginal thrush, rash, and raised pressure in the head (persistent headache with vision changes — seek care). Severe allergic reactions are rare but need urgent treatment.

Avoid prolonged sun exposure and use sunscreen, a hat, or protective clothing while on doxycycline, as sunburn can occur quickly. Take each dose with a full glass of water and stay upright for at least 30 minutes. Do not take antacids, calcium, iron, zinc, or milk within 2–3 hours of the dose, as they block absorption. Use with caution in liver disease and myasthenia gravis. Tell your doctor if diarrhoea becomes severe or watery during or after treatment.

Antacids and supplements containing calcium, magnesium, aluminium, iron, or zinc — and dairy products — greatly reduce doxycycline absorption; separate them by 2–3 hours. Doxycycline may enhance the effect of warfarin (bleeding risk), reduce the efficacy of some oral contraceptives, and its own levels are lowered by rifampicin, carbamazepine, and phenytoin. Avoid combining with isotretinoin or vitamin A (risk of raised intracranial pressure) and with penicillins where the doctor advises against it. Inform your doctor of all medicines you use.

Doxycycline must not be used by people allergic to tetracyclines. It is contraindicated in pregnancy and breastfeeding and in children under 12 years (except in special situations decided by a specialist), because it can permanently stain developing teeth and affect bone growth. It should be avoided in severe liver impairment unless a doctor judges it necessary.

Pregnancy: Doxycycline is contraindicated, particularly in the second and third trimesters, as it deposits in the baby's developing teeth and bones causing permanent discolouration and growth effects. Lactation: Avoid during breastfeeding. If you are pregnant, planning pregnancy, or breastfeeding, tell your doctor so a safer alternative antibiotic can be chosen.

Store below 30°C in a dry place, protected from light and moisture. Keep out of the reach of children. Never use doxycycline after its expiry date — outdated tetracyclines can become harmful to the kidneys. Keep capsules or tablets in the original blister until use.