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Doxacil 100 mg/gm Powder

Generic: Doxycycline

Manufacturer: Square Pharmaceuticals PLC, Pabna

Therapeutic class: Tetracycline Antibiotic

What is Doxacil?

Doxacil 100 mg/gm powder is a broad-spectrum tetracycline antibiotic from Square Pharmaceuticals PLC, Pabna containing Doxycycline. In Bangladesh it is widely prescribed for respiratory tract infections, acne, skin and soft-tissue infections, certain sexually transmitted infections, cholera, and rickettsial fevers such as typhus. It is also used for malaria prophylaxis in travellers when advised by a doctor.

Doxycycline works by binding to the bacterial ribosome and blocking protein synthesis, which stops bacteria from growing and multiplying so the immune system can clear the infection. Because it acts against a wide range of organisms — including atypical bacteria that many common antibiotics miss — it remains a dependable choice for chest infections, acne, and tropical infections in our region.

Indications

  • 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)

Dosage & Administration

Take Doxacil as your doctor directs. Adults usually start with 200 mg on the first day, then 100 mg once or twice daily; for acne, lower daily doses are used for several weeks. Swallow Doxacil with a full glass of water and remain sitting or standing upright for at least 30 minutes — lying down too soon can cause painful irritation or ulcers in the food pipe. Taking it with food reduces stomach upset. It is generally avoided in children under 12; any use in children must be decided by a doctor.

This is an antibiotic — complete the full prescribed course and never take it without a prescription.

Side Effects

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.

Precautions & Warnings

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.

Drug Interactions

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.

Contraindications

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 & Lactation

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.

Storage Conditions

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.

Frequently Asked Questions

How should I take Doxacil to avoid throat and stomach irritation?

Swallow Doxacil with a full glass of water, preferably with food, and stay sitting or standing upright for at least 30 minutes afterwards. Never take it just before lying down or at bedtime, as the capsule can stick in the food pipe and cause painful ulcers.

Can I go out in the sun while taking Doxacil?

Be careful. Doxycycline in Doxacil makes skin much more sensitive to sunlight, so you can get sunburn unusually fast. Avoid long sun exposure between 10am and 4pm, use sunscreen, and wear a hat or full-sleeve clothing while outdoors during the course.

Can I take Doxacil with milk or antacids?

No. Milk, antacids, and supplements containing calcium, iron, or zinc bind doxycycline in the gut and stop it from being absorbed, making Doxacil much less effective. Keep a gap of at least 2–3 hours between Doxacil and any of these products.

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