Tretiva (Isotretinoin) – Patient Information for Australia
Basic Product Information
| International Nonproprietary Name (INN) | Isotretinoin |
|---|---|
| Australian Brand Names | Tretiva, Roaccutane, Oratane, Accure, Isotroin |
| ATC Code | D10BA01 |
| Available Forms & Strengths | Capsules: 5 mg, 10 mg, 20 mg, 40 mg |
| Manufacturers | Cipla (India), Roche, Mylan, Douglas, and other approved manufacturers |
| Prescription Status | S4: Prescription Only Medicine (by an Australian registered doctor or dermatologist) |
Mechanism of Action
For Patients: Isotretinoin is a form of vitamin A that targets the main causes of severe acne. It dramatically reduces oil (sebum) production in the skin, shrinks oil glands, slows skin cell growth inside hair follicles (preventing clogging), and helps reduce inflammation. The result is clearer skin, often after a few months of treatment.
For Specialists: Isotretinoin modulates the transcription of genes involved in cell proliferation, differentiation, and apoptosis. It reduces sebaceous gland size and activity, suppresses Propionibacterium acnes proliferation, and has anti-inflammatory impacts via immunomodulatory properties.
Pharmacokinetics
- Absorption: Oral absorption is enhanced with high-fat meals. Bioavailability is roughly 25–50%, depending on food intake.
- Distribution: Highly protein bound (>99%). Extensively distributed in tissues.
- Metabolism: Metabolised in the liver via CYP enzymes to 4-oxo-isotretinoin (active).
- Elimination: Mainly via faeces (secondary renal route). Little risk of accumulation in healthy adults.
- Duration of Action: Terminal half-life 10–20 hours (parent compound); effect persists post-cessation because of deep tissue and metabolite activity.
Use in Everyday Life and Best Practices (Australia Context)
Isotretinoin is reserved for moderate to severe cystic acne that is resistant to other treatments (like topical therapy and oral antibiotics). In Australia, it is commonly prescribed by dermatologists and may be initiated in primary care under specialist direction. The treatment course usually lasts 4–8 months, depending on disease severity and total dose.
- Usual Dose: 0.5–1 mg/kg/day, divided into 1 or 2 daily doses.
- Intake: Take whole capsules with a glass of water, preferably with/after food.
- Pregnancy Warning: DO NOT USE in women who are pregnant, planning pregnancy, or breastfeeding. Reliable contraception is required for at least 1 month before, during, and 1 month after stopping isotretinoin.
- Blood tests: Regular liver function, lipid control, and pregnancy testing are required during treatment.
- Lifestyle: Avoid excess sunlight and tanning, waxing/hair removal, and donate blood during and for at least 1 month after therapy.
Dosing in the Morning vs Evening
- Morning Intake: Preferred if taken with breakfast (especially if this is the main or fattiest meal). Can help with adherence as part of the early day routine.
- Evening Intake: Some patients find evening dosing easier with their main meal. No significant difference in efficacy, but regularity (same time daily) is most important.
- Tip: Set a reminder and take isotretinoin at the same time with a main meal for best results.
Taking with Food or on an Empty Stomach (Effect of Meals & Australian Dietary Habits)
- With Food: Always take with food, ideally a meal containing fat (e.g. avocado toast, eggs, yogurt, cheese, or salmon).
- Without Food: Taking isotretinoin on an empty stomach may reduce absorption by up to 50%, making it much less effective.
- Best Practice: Align your intake with your usual meal times and dietary preferences for consistent absorption.
Interaction Warnings
| Interaction Source | Effect/Risk | Advice |
|---|---|---|
| Alcohol | May increase liver toxicity | Minimise or avoid alcohol during treatment |
| Vitamin A supplements | Risk of hypervitaminosis A (overdose symptoms) | Do not take vitamin A or multivitamins containing vitamin A |
| Tetracycline antibiotics | May increase risk of raised brain pressure | Avoid concurrent use |
| Other acne medications (retinoids, topical, etc.) | May increase skin irritation or toxicity | Use under direct supervision only |
| Contraceptive pills | Some antibiotics reduce pill effectiveness | Check with your doctor for suitable contraception |
| Phenytoin, St. John's wort | May interact with isotretinoin metabolism | Tell your doctor about all medications and supplements |
Indications
| Indication | Status | Details |
|---|---|---|
| Severe nodular/cystic acne | Approved | First-line for scarring or resistant forms |
| Moderate acne (refractory) | Approved | If failed oral antibiotics and topical therapy |
| Acne conglobata or fulminans | Off-label/approved under specialist | Exceptionally severe types, always specialist-led |
| Rosacea, hidradenitis suppurativa, some keratinisation disorders | Off-label | Only under dermatologist advice |
Dosing According to Clinical Indications
| Indication/Age Group | Initial Dose (mg/kg/day) | Average Total Duration | Notes |
|---|---|---|---|
| Adults (Acne) | 0.5–1.0 | 4–8 months | Adjust by tolerance and response |
| Adolescents (≥12 years) | 0.5, increase as tolerated | 4–6 months | Supervised by specialist |
| Elderly | As adults (lower end) | Tailored | Monitor for dehydration, joint pain |
| Off-label indications (e.g. rosacea) | 2–10 mg daily (low) | Customised | Specialist only |
Safety Profile & Side Effects
| Type | Examples | Advice |
|---|---|---|
| Very Common | Dry lips (cheilitis), dry skin, nosebleeds, increased skin sensitivity, dry eyes | Use moisturisers, lip balm, artificial tears; avoid sun, waxing |
| Common | Mild liver enzyme or cholesterol rise, back/joint pain, headache, tiredness | Monitor blood tests, stay hydrated, report severe pain |
| Rare/Serious | Vision changes, persistent headache, severe skin rash, mood/psychological effects (depression, suicidal thoughts) | Seek medical advice promptly |
| Pregnancy/Breastfeeding | Severe birth defects or miscarriage | Absolute contraindication—never use in pregnancy or while breastfeeding |
Guidelines for Proper Use (Australia-Specific Advice)
- Always follow the dosage instructions from your Australian doctor or dermatologist.
- Report side effects, especially mood changes, severe headaches, vision problems, or muscle pain immediately.
- Women of childbearing potential must use two forms of contraception and have regular pregnancy tests.
- Use high-SPF sunscreen and protect skin from harsh Australian sun exposure.
- Avoid waxing, dermabrasion, tattoos, and laser procedures during and 6 months after treatment.
- Carry a medical alert or pharmacy document stating you are taking isotretinoin.
Alternative Treatment Options (PBS-Listed Reimbursed Medications)
- Oral antibiotics: Doxycycline, Minocycline, Erythromycin (often first-line but less effective in severe cases, PBS-listed)
- Topical retinoids: Adapalene, Tretinoin (fewer side effects, slower response)
- Oral contraceptives: Certain types for women only, useful for acne with hormonal component
- Other systemic therapies: Spironolactone (women), low-dose corticosteroids for severe/inflammatory subtypes
Isotretinoin is the only therapy proven to target all causal aspects of nodulocystic acne and reduce recurrence, but it has higher risk of adverse effects and specific monitoring requirements.
Legal, Registration, and Reimbursement Status in Australia
- Regulator: Listed on the Australian Register of Therapeutic Goods (ARTG/TGA)
- Prescription: S4 (by prescription only)
- Reimbursement: Subsidised for eligible patients via the PBS (Pharmaceutical Benefits Scheme)
- Supply: PBS prescriptions limited to 2 months’ supply, repeats with ongoing review by your doctor
Latest Research and Clinical Guidance (2022–2025)
- Recent systematic reviews (DermNet NZ 2023; NCBI Book: Isotretinoin 2024) confirm isotretinoin remains the gold-standard for severe or recalcitrant acne, offering remission rates above 85% when given to cumulative target doses (120–150 mg/kg).
- A growing body of evidence supports lower-dose, longer-duration ("micro-dosing") in certain patients to reduce side effects (TGA 2022), especially for adult women and those with tolerability concerns.
- National and international guidelines (e.g., Australasian College of Dermatologists) recommend isotretinoin be prescribed only after careful risk–benefit assessment, with particular attention to contraception and psychiatric history screening.
Availability and Delivery
| Strength | Popular Pack Sizes | Indicative PBS Price (AUD, Jan 2024) | Delivery: Sydney/Melbourne/Brisbane (business days) |
|---|---|---|---|
| 10 mg | 60, 120 capsules | $30–45 (with PBS, for up to 2 months) | 1–2 |
| 20 mg | 60, 120 capsules | $30–55 (with PBS) | 1–2 |
| 40 mg | 30, 60 capsules | $50–70 (with PBS) | 1–3 |
- Online and community pharmacy dispensing is subject to prescription validation and in-person ID check.
- Rural and regional delivery may take 3–5 business days.
- Delivery fees vary between pharmacy providers; some offer free pick-up from store.
Frequently Asked Questions (FAQ)
- Q: How long does it take to see results?
A: Most patients notice improvement within 6–8 weeks. Maximum benefit is seen after 4–6 months of therapy. Some people experience an initial temporary acne flare. - Q: Can I drink alcohol while taking isotretinoin?
A: Moderate alcohol may further increase strain on your liver, so it’s safest to limit or avoid alcohol while on treatment. - Q: What should I do if I miss a dose?
A: Take the missed dose with your next meal if within 12 hours of your usual time. Otherwise, skip the dose—do not double up. - Q: Is it normal for my skin/lips to become very dry?
A: Yes; dry skin and lips are the most common side effects. Use unscented moisturisers and lip balms regularly. - Q: Will my acne come back after stopping?
A: Most people stay clear for months or years after completing their course. A minority may need further or repeat courses as directed by their doctor.
For more information, speak to your doctor, pharmacist, or visit the Therapeutic Goods Administration (TGA) website. Always use this medicine exactly as prescribed and do not share it with others.
