What conditions is cannabis FDA-approved for?

FDA-Approved Cannabis-Based Medications

The FDA has approved three specific cannabinoid medications: Epidiolex (cannabidiol/CBD) for rare epilepsy syndromes and tuberous sclerosis complex, and dronabinol and nabilone (synthetic THC compounds) for chemotherapy-induced nausea/vomiting and AIDS-related anorexia. 1

Specific FDA-Approved Indications

Epidiolex (Cannabidiol/CBD)

• Lennox-Gastaut syndrome - approved in 2018 1
• Dravet syndrome - approved in 2018 1
• Tuberous sclerosis complex - approved in 2020 1
• This is the only FDA-approved medication containing plant-derived CBD as of January 2024 1
• Epidiolex was descheduled from the Controlled Substances Act in 2020 1

Dronabinol (Synthetic THC)

• Chemotherapy-induced nausea and vomiting in patients who have failed conventional antiemetics 1, 2
  • Starting dose: 5 mg/m² administered 1-3 hours prior to chemotherapy, then every 2-4 hours after chemotherapy for 4-6 doses per day 2
• Anorexia associated with weight loss in AIDS patients 1, 2
  • Starting dose: 2.5 mg orally twice daily, one hour before lunch and dinner 2
• First approved in 1985 2, 3

Nabilone (Synthetic Cannabinoid)

• Chemotherapy-induced nausea and vomiting as an antiemetic 1
• Chemically similar to THC but synthetically derived 1
• Also approved in 1985 3

Critical Distinction: Medical Marijuana vs FDA-Approved Cannabinoids

Medical marijuana itself has NOT been FDA-approved for any indication, despite legalization in many states. 1 This creates an important clinical distinction:

• Cannabis remains a Schedule I controlled substance federally, classified as having "no currently accepted medical use" and "high potential for misuse" 1
• 38 states and Washington, DC have legalized medical cannabis as of April 2023, creating federal-state legal divergence 1
• The FDA-approved cannabinoids (dronabinol, nabilone, Epidiolex) have precisely defined doses and schedules, which medical marijuana preparations lack 1

Current Role in Clinical Practice

Chemotherapy-Induced Nausea and Vomiting

• Cannabinoids are not recommended as first-line treatment 3
• Reserved for breakthrough nausea and vomiting or refractory cases after failure of conventional antiemetics (5-HT3 antagonists, dexamethasone, NK1 antagonists) 1
• Evidence for cannabinoids predates modern antiemetic regimens (trials conducted 1975-1991), limiting applicability 1, 4
• When choosing a cannabinoid for rescue therapy, dronabinol or nabilone are recommended over medical marijuana due to standardized dosing 1

Pain Management

• Evidence for cannabis in chronic pain is inconsistent 1
• A 2022 meta-analysis concluded cannabis products "may be associated with short-term improvements in chronic pain and increased risk for dizziness and sedation" 1
• Data supporting cannabinoids as adjuvant analgesics for cancer pain are "extremely limited" with conflicting results 1

Epilepsy

• Epidiolex represents the strongest evidence for cannabinoid efficacy, with demonstrated effectiveness in reducing seizure frequency in tuberous sclerosis complex and rare epilepsy syndromes 5
• Open-label studies suggest potential effectiveness in other epilepsy syndromes including CDKL5 deficiency disorder, Aicardi syndrome, and Doose syndrome 5

Common Adverse Effects

Most frequent adverse reactions (≥3%) with dronabinol: 2

• Abdominal pain
• Dizziness
• Euphoria
• Nausea (paradoxical)
• Paranoid reaction
• Somnolence
• Abnormal thinking
• Vomiting

Comparative adverse effects with cannabinoids vs prochlorperazine: 4

• Significantly higher rates of dizziness (RR 2.4), dysphoria (RR 7.2), euphoria (RR 18), "feeling high" (RR 6.2), and sedation (RR 1.4) with cannabinoids 4

Critical Safety Warnings

Contraindications

• Absolute contraindication: History of hypersensitivity to dronabinol or sesame oil 2

High-Risk Populations Requiring Caution

• Pregnant and breastfeeding individuals - FDA and Surgeon General advise complete avoidance due to potential fetal brain development effects and increased premature birth risk 1
• Adolescents - cannabis use associated with neurodevelopmental decline, elevated psychotic disorder risk, depression, and suicidal ideation 1
• Elderly patients (≥65 years) - higher risk for behavioral health issues (anxiety, depression), sedation, obtundation, and myocardial ischemia/infarction 1
• Patients with psychiatric history - avoid use due to risk of psychiatric and cognitive effects; THC may exacerbate psychotic symptoms 2
• Cardiac disorders - risk of hypotension, hypertension, syncope, or tachycardia 2
• Seizure history - weigh risks versus benefits; monitor and discontinue if seizures occur 2
• Substance abuse history - assess risk for abuse/misuse prior to prescribing; monitor for cannabis use disorder development 2

Paradoxical Effects

• Cannabis can cause or exacerbate the same conditions it is intended to treat (nausea, vomiting, seizures) depending on THC content 1, 6
• Consider dose reduction or discontinuation if symptoms worsen during treatment 1

Clinical Monitoring Requirements

When prescribing FDA-approved cannabinoids, monitor for: 2

• Neuropsychiatric symptoms (cognitive impairment, mood changes, psychosis)
• Hemodynamic changes after initiation or dose increases
• Seizure activity in at-risk patients
• Signs of cannabis use disorder (irritability, insomnia, headaches with withdrawal) 1
• Driving impairment - patients should not operate vehicles until reasonably certain the medication does not cause adverse effects 2