Accutane (Isotretinoin) and Cannabis: Full Interaction Profile

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Does cannabis interact with isotretinoin?

The Absorica and Absorica LD label's drug interactions section is short. It says to avoid vitamin A supplements, avoid tetracyclines, and notes that isotretinoin did not cause clinically significant pharmacokinetic changes in norethindrone and ethinyl estradiol given as an oral contraceptive [1]. The older Accutane label adds St. John's Wort, phenytoin, micro-dosed progesterone preparations and systemic corticosteroids [3]. Cannabis, THC and CBD are not named in either label [1][3].

Research does link heavy cannabis use with higher odds of developing depression, while isotretinoin labeling covers psychiatric disorders, lipid abnormalities and hepatotoxicity.

How isotretinoin is handled by the body

Isotretinoin absorption depends heavily on food. In 74 healthy adults given a single 80 mg dose, a high-fat meal more than doubled total exposure, with AUC 10,004 vs 3,703 ng·h/mL and peak concentration 862 vs 301 ng/mL; half-life was about 21 hours either way [3]. The drug is more than 99.9% protein bound, and in-vitro work points to CYP2C8, 2C9, 3A4 and 2B6 as the metabolizing enzymes [3]. Its main metabolite, 4-oxo-isotretinoin, reaches steady-state exposure about 3.4 times that of the parent drug [3].

Mood and psychiatric effects

The label states that isotretinoin may cause depression, psychosis and, rarely, suicidal ideation, suicide attempts, suicide and aggressive or violent behaviors. It directs prescribers to ask about psychiatric history before treatment and to assess for depression, mood disturbance, psychosis or aggression at each visit. It also says that patients who develop these symptoms should immediately stop the drug and promptly contact their health care provider [1]. The older Accutane label states: 'No mechanism of action has been established for these events' [3].

Cannabis has its own mood literature. A meta-analysis of 14 longitudinal studies covering 76,058 people found an odds ratio of 1.17 (95% CI 1.05 to 1.30) for developing depression among cannabis users versus controls, and 1.62 (95% CI 1.21 to 2.16) for heavy users versus non-users or light users [2]. A separate meta-analysis of 35 samples found that 33.7% of people were current cannabis users at the time of a first episode of psychosis, which is a prevalence figure and not a measure of what caused the episode [4].

The label does not quantify a combined risk with cannabis [1][3]. In someone taking both, mood symptoms could have more than one contributor, and the label calls for assessment at every visit [1].

Triglycerides and liver enzymes

The Accutane label reports marked elevations of serum triglycerides in approximately 25% of patients in clinical trials, a decrease in high-density lipoprotein in about 15%, and a rise in cholesterol in about 7%; triglyceride elevations above 800 mg/dL have been reported [3]. Those lipid effects were reversible when the drug was stopped, and some patients reversed triglyceride elevation with weight reduction, restriction of dietary fat and alcohol, and a lower dose while continuing treatment [3]. The label calls for lipid determinations before treatment and then at intervals until the response is established, which usually happens within 4 weeks, with more frequent checks in patients who have diabetes, obesity, increased alcohol intake or a lipid metabolism disorder [3].

Hepatotoxicity is one of the labeled warnings, and the label directs liver function tests before and during treatment [1]. Hepatitis appears among the labeled adverse reactions [1].

What gets monitored during treatment

The label's own checklist is straightforward. Fasting lipid profile and liver function tests are completed in all patients before prescribing [1]. Psychiatric history and current symptoms are reviewed before treatment and at each visit [1]. Lipid levels are checked at regular intervals [3]. The label says that if depression, mood disturbance, psychosis or aggression occurs, the patient should immediately stop the drug and promptly contact their health care provider, and that treatment should be stopped if hypertriglyceridemia cannot be controlled [1][3].

Isotretinoin is available only through the iPLEDGE REMS. Every patient is enrolled, and pharmacies dispense a maximum 30-day supply with no refills [1].