Siadocin Doxycycline 100 mg Antibiotic Capsule

Doxycycline 100 mg should always be used as directed by a doctor or pharmacist. General adult dosages are as follows:

Common Dosages

• Inflammatory acne: 100 mg once daily for 6–12 weeks
• Respiratory tract infections: 100 mg once or twice daily as prescribed
• STDs (Chlamydia, Syphilis): 100 mg twice daily for 7–14 days

How to Take

• Take with or after food to reduce nausea
• Drink at least 240 ml of water with each dose
• Do not lie down within 30 minutes of taking (prevents esophageal ulceration)
• Avoid milk, calcium supplements, and antacids within 2 hours before or after dosing (chelation reduces absorption)
• Avoid prolonged sun exposure; use SPF 30+ sunscreen while on treatment

⚠️ Complete the full course even if symptoms improve.

Doxycycline 100 mg is approved for the following indications:

1. Inflammatory Acne

An effective oral antibiotic for acne that reduces Cutibacterium acnes and suppresses inflammation simultaneously. Indicated for moderate-to-severe inflammatory acne unresponsive to topical treatments.

2. Respiratory Tract Infections

Treats atypical pneumonia (Mycoplasma pneumoniae, Chlamydophila pneumoniae) and chronic bronchitis.

3. Sexually Transmitted Infections (STI)

First-line treatment for Chlamydia, gonorrhea (non-penicillinase-producing strains), and syphilis in penicillin-allergic patients.

4. Other Infections

• Lyme disease (tick-borne)
• Rickettsia infections
• Malaria prophylaxis

Common Side Effects

• Nausea, vomiting, or stomach upset (reduced by taking with food)
• Photosensitivity — avoid prolonged sun exposure
• Diarrhea
• Headache, dizziness
• Skin rash

Less Common but Important

• Esophageal ulceration — prevented by drinking plenty of water and not lying down
• Vaginal yeast infection
• Pseudomembranous colitis (rare)

Contraindications

• Children under 8 years (risk of tooth discoloration and bone effects)
• Pregnancy and breastfeeding
• Known hypersensitivity to tetracyclines

Doxycycline has clinically important interactions with several medications and substances.

Substances That Reduce Doxycycline Absorption

• Antacids (aluminum/magnesium) — space at least 2 hours apart
• Iron supplements / Calcium — chelation significantly reduces absorption
• Milk / Dairy — high calcium; take 2 hours apart
• Bismuth subsalicylate

Other Key Interactions

• Warfarin — may enhance anticoagulant effect; monitor INR closely
• Oral contraceptives — may reduce efficacy; use backup contraception
• Penicillins — avoid combining (bacteriostatic vs bactericidal antagonism)
• Retinoids (e.g. isotretinoin) — increased risk of intracranial hypertension

Oral antibiotics differ in spectrum and indication. Here is a quick comparison:

Siadocin — Doxycycline 100 mg

Best for: inflammatory acne, atypical pneumonia, STIs (Chlamydia, syphilis), Lyme disease | Tetracycline class | bacteriostatic

AMK (Amoxicillin) — Gram-positive spectrum

Best for: respiratory infections, otitis media, H. pylori | Penicillin class | bactericidal

Augmentin (Amoxicillin+Clavulanate) — broader than Amoxicillin

Best for: beta-lactamase-producing organisms; combines amoxicillin with clavulanate inhibitor

Cobay-500 (Ciprofloxacin) — Gram-negative spectrum

Best for: UTI, bacterial diarrhea, intra-abdominal infections | Fluoroquinolone | bactericidal

Cifloxin (Ciprofloxacin) — Gram-negative spectrum

Same active ingredient as Cobay-500; alternative brand for urinary and GI tract infections

Metrolex (Metronidazole) — Anaerobes & Parasites

Best for: anaerobic infections, Trichomoniasis, Giardia, bacterial vaginosis | bactericidal vs anaerobes

Summary: Siadocin (Doxycycline) is the first choice for oral acne treatment and Chlamydia/Syphilis STIs. Amoxicillin covers Gram-positive infections; Ciprofloxacin targets Gram-negative organisms.

Manufacturer

Siam Bheasach Co., Ltd.
Bangkok, Thailand

Drug Registration

Registration No.: 1A 145/39

Dosage Form

• Form: Capsule
• Strength: 100 mg Doxycycline HCl per capsule
• Pack size: 10 capsules per box

Storage

Store in a dry place below 30°C, away from direct sunlight. Keep out of reach of children.

Explore related medications and products in the following collections:

• Doxycycline — All products containing Doxycycline
• Antibiotics — Complete range of antibacterial medications
• Acne Treatments — Oral and topical acne medications

Buy Online at Intimo Life

Intimo Life stocks authentic Siadocin (Doxycycline 100 mg) with nationwide delivery across Thailand. Orders are shipped in plain, discreet packaging—no product name shown. Available to order 24/7.