Isotretinoin

Isotretinoin is a vitamin A derivative (retinoid) that is taken in capsule form. Originally known under the brand name Roaccutan®, it is now available as a generic.

Isotretinoin is used for severe, scarring, or treatment-resistant acne when other treatments have failed. A typical course of treatment lasts 4-6 months and leads to lasting improvement or cure in most patients.

Because of the risk of birth defects, strict pregnancy prevention is required for women.

Isotretinoin acts on all the factors involved in the development of acne:

1. Sebum production:

• Reduces the size and activity of the sebaceous glands
• Sebum production decreases by up to 90%
• This effect often lasts permanently

2. Keratinization disorder:

• Normalizes keratinization in the follicles
• Prevents clogging of the pores
• Comedones (blackheads) are reduced

3. Bacteria:

• Indirectly antibacterial due to less sebum
• P. acnes finds less of a breeding ground
• Reduced colonization of the follicles

4. Inflammation:

• Anti-inflammatory effect
• Reduces redness and swelling
• Prevents scarring

Isotretinoin is suitable for:

• Severe nodular/cystic acne
• Treatment-resistant moderate acne
• Acne with a high risk of scarring
• Acne causing severe psychological distress
• Acne that does not respond to antibiotics

Strict requirements:

• Women: reliable contraception (at least one highly reliable user-independent method or two complementary user-dependent methods), monthly pregnancy tests
• Everyone: regular blood tests and liver enzyme checks
• Informed consent after counseling

Not suitable in cases of:

• Pregnancy (absolutely contraindicated)
• Breastfeeding
• Severe liver disease
• Very high blood lipids

Standard dosage:

• Start: 0.5 mg/kg/day
• Increase to: 0.5-1 mg/kg/day
• Typical: 40-80 mg/day in adults

Cumulative total dose:

• Target: 120-150 mg/kg over the entire course of treatment
• At 70 kg: about 8,400-10,500 mg in total
• Corresponds to 4-6 months of treatment

Low-dose long-term therapy:

• Alternatively: 10-20 mg/day over a longer period
• For patients with severe side effects

Available strengths:

• Capsules: 10 mg, 20 mg, 40 mg

How to take it:

• Take with a meal (containing fat for better absorption)
• Swallow capsules whole, do not chew
• Always at about the same time of day
• For doses >40 mg: split into two doses

During treatment:

• No blood donation (until 1 month after the end of treatment)
• No waxing
• Consistent sun protection (SPF 30+)
• No vitamin A supplements
• Drink plenty of water
• Lip care and moisturizer

Follow-up tests:

• Before treatment: liver enzymes, blood lipids, pregnancy test
• Monthly: pregnancy test (women)
• Regularly: liver enzymes, blood lipids (every 1-2 months)

Isotretinoin must NOT be used in cases of:

• Pregnancy (absolutely contraindicated – severe birth defects!)
• Breastfeeding
• Women without reliable contraception
• Severe hepatic insufficiency
• Very high blood lipids (hypertriglyceridemia)
• Hypervitaminosis A
• Concurrent tetracycline therapy

Pregnancy prevention program:

• At least one highly reliable user-independent contraceptive method or two complementary user-dependent methods (e.g., pill + condom)
• Start 1 month before therapy
• Until 1 month after the end of therapy
• Monthly pregnancy tests
• No pregnancy during therapy + 1 month afterward

Caution in cases of:

• Depression or mental illness
• Diabetes mellitus
• Contact lens wearers (dryness)

Very common (>10%):

• Dry skin and lips (practically all patients)
• Nosebleeds, dry nose
• Dry eyes, contact lens intolerance
• Joint pain, muscle pain
• Elevated liver enzymes
• Elevated blood lipids

Common (1-10%):

• Skin sensitivity
• Tendency to sunburn
• Hair loss (reversible)
• Headache
• Fatigue

Psychological side effects:

• Mood changes, depression (rare, but be aware)
• If there are any signs, inform a doctor immediately!

Rare but serious:

• Pseudotumor cerebri (severe headache, visual disturbances)
• Inflammatory bowel disease
• Severe skin reactions

Long-term effects: Most side effects disappear after the end of therapy.

Contraindicated:

• Tetracyclines (doxycycline, minocycline) – increased risk of pseudotumor cerebri
• Vitamin A – hypervitaminosis
• Other retinoids

Caution with:

• Methotrexate – increased liver toxicity
• St. John's wort – can make contraceptives ineffective
• Alcohol – greater increase in liver enzymes

Hormonal contraception: Low-dose progestin pills may be less reliable. Combination pills or an additional barrier method are recommended.