Cannabis Use Disorder (CUD) - Clinical Management Plan

CLINICAL FORMULATION

• Inability to quit despite desire (loss of control)
• Withdrawal symptoms on cessation (anger/irritability, manic-like agitation)
• Tolerance (hallucinations that no longer occur - a sign of neuroadaptation)
• Continued use despite psychological harm (depression post-use)
• Long-term heavy use since college (>15 years)
• Drowsiness, numbness, palpitations = intoxication effects

Rx PRESCRIPTION

PHASE 1: DETOXIFICATION / WITHDRAWAL MANAGEMENT (Week 1-4)

1st Line - Symptom Management

Tab. Buspirone 5 mg TID x 1 week, then titrate to 10 mg TID (30 mg/day) x 8-12 weeks

• Mechanism: 5-HT1A partial agonist; anxiolytic without abuse potential
• Evidence: Randomized controlled trials examined buspirone up to 60 mg/day in cannabis-dependent patients; it showed benefit in reducing irritability and anxiety during withdrawal, though outcomes for long-term abstinence have been mixed (Kaplan & Sadock's Comprehensive Textbook of Psychiatry)

Tab. Zolpidem 5-10 mg at bedtime x 2 weeks MAXIMUM (taper off)

• OR Tab. Nitrazepam 5 mg at bedtime x 1-2 weeks
• Note: Benzodiazepines and zolpidem have been used to manage sleep disturbance in cannabis withdrawal (Kaplan & Sadock's CTP). Use the shortest effective course - do NOT continue beyond 2 weeks given addiction risk.
• Alternative (preferred if prolonged sleep trouble): Tab. Mirtazapine 7.5-15 mg at bedtime - has added benefit of appetite stimulation and anxiolysis; no abuse potential

Tab. Sertraline 50 mg OD in the morning (titrate to 100 mg after 4 weeks if needed)

• SSRIs are used when cannabis use appears to be compounding or masking an underlying depressive disorder (Kaplan & Sadock's Synopsis of Psychiatry; Goodman & Gilman's)
• Continue for minimum 6 months after achieving abstinence
• Note: The depressive symptoms may resolve with sustained abstinence alone; reassess at 4-6 weeks of sobriety before deciding to continue SSRI long-term

2nd Line - Persistent Symptoms / If 1st Line Insufficient

Tab. Gabapentin 300 mg TDS (900 mg/day), may titrate to 1200 mg/day

• A proof-of-concept RCT (Mason et al., 2012) demonstrated gabapentin reduced cannabis use, attenuated withdrawal severity, and improved executive function deficits in cannabis-dependent adults
• Also useful for residual anxiety and sleep disruption
• Textbook of Family Medicine 9e notes ongoing studies for gabapentin in cannabis withdrawal

Tab. Quetiapine 25-50 mg at night (low-dose)

• Useful for severe agitation, insomnia, and mood dysregulation during withdrawal
• Avoid long-term use unless a primary bipolar or psychotic disorder is confirmed

PHASE 2: RELAPSE PREVENTION & CRAVING REDUCTION (Month 2-6)

For Craving Reduction (this is a key concern in this patient):

Tab. NAC 1200 mg twice daily (2400 mg/day)

• Mechanism: Restores glutamate homeostasis in the nucleus accumbens; reduces incentive salience and drug craving
• Evidence: RCTs (Gray et al.) showed NAC significantly reduced cannabis craving and use, particularly in adolescents and young adults. It is well-tolerated with a strong safety profile
• Continue for 3-6 months; reassess
• This is currently among the most studied and clinically supported agents for cannabis craving reduction

PHASE 3: PSYCHOSOCIAL INTERVENTIONS (CONCURRENT - MANDATORY)

LIFESTYLE MODIFICATIONS

SIDE EFFECTS OF PRESCRIBED DRUGS

⚠️ CRITICAL DRUG INTERACTIONS & WHAT TO AVOID DURING ACTIVE CANNABIS USE

This is the most safety-critical section if the patient relapses or has breakthrough cannabis use during therapy.

1. Sertraline + Cannabis

• THC has CNS depressant and serotonergic-adjacent activity. Concurrent use can cause excessive sedation, cognitive blunting, and possible serotonin syndrome risk (theoretical - case reports exist)
• Cannabis-induced depressive episodes may mask or worsen SSRI response, making treatment assessment unreliable
• Action: Do NOT stop SSRI abruptly; continue, but escalate psychosocial support and notify treating physician

2. Zolpidem / Benzodiazepines + Cannabis

• HIGH RISK - AVOID: Both are CNS depressants. Additive CNS depression causes excessive sedation, respiratory depression (especially at high doses), impaired coordination, and significant road safety risk
• Do NOT prescribe zolpidem/nitrazepam if patient is still actively using cannabis
• If sleep medication is required during active use: use Mirtazapine instead (safer pharmacokinetic profile)

3. Gabapentin + Cannabis

• Additive CNS depression - excess sedation, dizziness, falls risk
• Caution: Use lowest effective dose; warn patient of increased impairment if cannabis is used concurrently

4. Quetiapine + Cannabis (if prescribed)

• Both cause QTc prolongation (cannabis via sympathetic stimulation can cause palpitations + arrhythmia risk)
• Additive anticholinergic effects and sedation
• Avoid combination at higher quetiapine doses; if used, ensure cardiac monitoring (ECG)

5. Buspirone + Cannabis

• Buspirone's anxiolytic effect is significantly blunted by concurrent THC (pharmacodynamic antagonism at 5-HT1A during acute cannabinoid stimulation)
• Therapeutic effect is reduced; patient may perceive medication as "not working" leading to self-escalation
• Counsel: Buspirone will not work optimally if cannabis is still being used - this is itself a motivation for abstinence

6. NAC + Cannabis

• No dangerous interaction; NAC may actually reduce the rewarding effects of cannabis through glutamate pathway modulation - beneficial during the quit process even if patient has breakthrough use

SUMMARY DRUG TABLE

MONITORING PLAN

• Week 1, 2, 4: In-person review of withdrawal symptoms, mood, sleep, suicidal ideation (SSRI initiation)
• Week 4, 8, 12: Urine drug screen for THC; liver function (if using gabapentin long-term); weight and metabolic parameters (if on quetiapine)
• Month 3, 6: Reassess mood - if depression resolves with sustained abstinence, plan SSRI taper; reassess need for continued pharmacotherapy
• Ongoing: CBT + MET sessions; Marijuana Anonymous attendance logs

Disclaimer: This prescription plan is for educational and clinical guidance purposes. All prescriptions must be issued by a licensed physician after direct patient evaluation, local regulatory compliance, and consideration of individual patient factors.