A Pharmacist's Guide to Medical Marijuana: Uses, Risks, and Legal Complexity | Research

The takeaway

As of 2007, 11 US states had legalized medical marijuana for conditions including nausea, weight loss, spasticity, and pain, but pharmacists had limited guidance on interactions and patient counseling.

Read this if you want historical context on how the medical marijuana conversation looked from a pharmacy perspective in 2007.

11 US states had legalized medical marijuana by 2007, but pharmacists had limited guidance

What the researchers found

This review outlined the pharmacological, therapeutic, and legal landscape of medical marijuana for pharmacists as of 2007.

The authors identified five general indications with varying levels of evidence: chemotherapy-induced nausea, weight loss from debilitating illness (HIV, cancer), spasticity from neurological diseases, pain syndromes, and other uses including glaucoma.

The review cataloged known adverse effects across psychiatric, cardiovascular, respiratory, and immunologic domains, and highlighted potential drug-drug interactions and disease-state interactions that pharmacists should be aware of.

A key practical challenge was noted: since marijuana remained a Schedule I controlled substance under federal law, patients using state-legal medical marijuana might never interact with a pharmacist, creating a gap in patient safety.

Why it matters

This review highlighted a unique problem in medical marijuana: it occupied a legal gray zone where patients used it medicinally but without the pharmaceutical infrastructure (pharmacist counseling, interaction screening, quality control) that exists for other medications.

The numbers in context

Over 460 active chemicals and 60+ unique cannabinoids in marijuana. 11 US states had legalized medical marijuana as of 2007. Five general medical indications were identified.

How the study worked

Narrative review of published literature on marijuana pharmacology, therapeutic uses, safety profile, drug interactions, and legal status. Organized as a practical reference for pharmacists.

What this study cannot tell us

As a narrative review from 2007, the evidence base was limited. The legal landscape has changed dramatically since publication. Drug interaction data for cannabis remained sparse and largely theoretical.

How to read the evidence

This is a narrative review providing an overview for practitioners. It synthesizes existing knowledge but does not add new data.

When this study was published

Published in 2007. The US landscape has changed dramatically: as of 2024, over 40 states have some form of legal medical cannabis, and several have recreational legalization.

The bigger picture

The challenges identified in this 2007 review, including the federal-state legal conflict, lack of pharmacist involvement, and limited interaction data, remain relevant as medical cannabis programs have expanded to the majority of US states.

Questions still open

How should pharmacists integrate medical marijuana into drug interaction screening? Can standardized cannabis products be developed that fit into existing pharmaceutical frameworks?

Common questions

Why are pharmacists relevant to medical marijuana?

Pharmacists are drug interaction experts who screen for dangerous combinations. Since medical marijuana patients often take other medications, pharmacist involvement could improve safety. However, marijuana's federal scheduling has historically excluded it from pharmacy practice.

What drug interactions were identified?

The review noted that marijuana can interact with medications metabolized by similar liver enzymes, with sedating drugs, and with medications affecting cardiovascular function. Specific interactions were not well characterized at the time.

Read the original research

Medical marijuana and the developing role of the pharmacist.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 64(10), 1037-44

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Citation

Seamon, Matthew J; Fass, Jennifer A; Maniscalco-Feichtl, Maria; Abu-Shraie, Nada A. (2007). Medical marijuana and the developing role of the pharmacist.. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 64(10), 1037-44.