Effects of Isotretinoin on CYP2D6 Activity

In this aim, we will conduct a drug-drug interaction study evaluating the effects of
13-cis-retinoic acid on non-induced CYP2D6 activity in adolescent patients. Secondary
analysis will evaluate the relationship between retinoid concentrations and CYP2D6 activity
in these special populations

Inclusion Criteria:

- Non-pregnant

- ≥ 12 years

- Patients with severe acne that are expected to receive isotretinoin for therapeutic
reasons

Exclusion Criteria:

- Weight < 80 lbs

- Allergy or adverse reaction to dextromethorphan, vitamin A or isotretinoin

- Pregnant or planning to become pregnant

- Unable to follow isotretinoin risk evaluation and mitigation strategies (REMS) program
(also known as iPLEDGE program)

- Chronic or persistent cough accompanying asthma, smoking or COPD,

- Productive cough,

- Fever,

- Known kidney disease,

- Known liver disease,

- Diabetes

- Obesity, BMI ≥ 30 kg/m2

- Bipolar disease,

- Attention deficit disorder,

- Social phobia,

- Concurrent or use within 14 days of drugs known to interact with DM or CYP2D6 or drugs
known to increase the risk of adverse effects from DM

- Concurrent use of any other product containing dextromethorphan

- Consuming foods, beverages or dietary supplements known to interact with DM or CYP2D6

- Unable to give written informed consent/assent,

- Inability to fast for 4 hours prior to study.

- Wards of the State