Medication, substance-use, washout, and taper management

The manuals converge on careful review of concomitant medications and psychoactive substance use before dosing, with repeated attention to washout, tapering, and documentation. Across the extracts, the common pattern is to reconcile current and prior medications, confirm that prohibited agents have been stopped, and monitor for withdrawal, destabilisation, or other safety issues during taper periods. Several sources also link this work to coordination with treating clinicians, study physicians, or outside prescribers, especially when medication changes affect eligibility or interpretability. They also agree that abstinence and timing restrictions matter around dosing sessions, but the exact restrictions differ by protocol and substance. Some manuals focus on antidepressants, antipsychotics, MAOIs, and other psychotropics, while others add benzodiazepines, sleep medicines, decongestants, corticosteroids, psychostimulants, alcohol, nicotine, caffeine, cannabis, herbal products, or specific agents such as sildenafil and tadalafil. The washout windows also vary, ranging from half-life based approaches to fixed periods such as 2 weeks, 4 weeks for fluoxetine, or 5 weeks for fluoxetine in one guideline. The sources differ most in how much they emphasise participant counselling versus sponsor or team escalation. Some manuals stress verbal verification, urine drug screening, breathalyser checks, and support-person or family education, while others explicitly mention sponsor notification when prohibited therapies are administered.