What treatment plan would be most effective for a 35-year-old female patient with a history of Substance Use Disorder (SUD)/Opioid Use Disorder (OUD), endocarditis, scoliosis, Post-Traumatic Stress Disorder (PTSD), anxiety, depression, and chronic pain, who is currently taking Sublocade (buprenorphine) 300mg, Mirtazapine (Remeron) 30mg, and Prazosin 3mg, and is experiencing significant weight gain and ineffective anxiety management?

Treatment Plan for 35-Year-Old Female with OUD, PTSD, Depression, and Chronic Pain

Continue Sublocade 300mg Monthly

Continue Sublocade 300mg monthly injections as the patient is responding well, with sustained therapeutic buprenorphine levels maintained throughout the dosing interval. 1, 2 The patient's positive response and stability on this regimen should be maintained, as monthly extended-release buprenorphine provides sustained plasma concentrations that control withdrawal, craving, and block opioid effects while eliminating diversion risks. 2

• Sublocade delivers therapeutic concentrations from the first injection and maintains them over the entire treatment duration, with mean abstinence rates of 41-43% compared to 5% for placebo. 2
• The monthly depot formulation is particularly appropriate for patients with recent incarceration history, as it eliminates concerns about medication diversion or misuse. 2
• Reassess every 3 months for continued benefit, monitoring for sustained improvement in opioid abstinence and functional outcomes. 3

Address Chronic Scoliosis Pain

For chronic scoliosis-related pain, increase the Sublocade dose by dividing it into more frequent dosing or add multimodal non-opioid analgesics rather than adding full opioid agonists. 3

• Buprenorphine in divided doses (4-16mg every 6-8 hours) has shown benefit for chronic non-cancer pain, with 86% of patients experiencing moderate to substantial pain relief. 3
• Since the patient is on Sublocade 300mg monthly, consider adding adjuvant therapy including acetaminophen (avoiding NSAIDs due to her rash history beyond 1-2 days), topical agents, and physical therapy modalities. 3
• Approve her request for yoga and exercise, as these non-pharmacologic interventions are first-line for chronic musculoskeletal pain. 3
• If pain remains inadequately controlled despite these measures, consider adding a long-acting potent opioid such as morphine or hydromorphone at higher-than-typical doses (buprenorphine's high mu-receptor affinity blocks lower doses of other opioids). 3

Optimize Anxiety Management

Replace prazosin with an evidence-based first-line anxiety treatment, as prazosin is ineffective for her generalized anxiety symptoms. 4

• While prazosin can help with PTSD-related nightmares and sleep disturbances, this patient reports it is not controlling her anxiety. 4
• Consider initiating an SSRI (sertraline 50-200mg daily) or SNRI (venlafaxine XR 75-225mg daily) as first-line pharmacotherapy for both PTSD and generalized anxiety. 5
• Alternative options include buspirone 15-60mg daily in divided doses or gabapentin 900-3600mg daily in divided doses, both of which avoid benzodiazepines (contraindicated with buprenorphine due to respiratory depression risk). 5
• Wait until she is more settled in her program (2-4 weeks) before making this change to avoid destabilizing her during early recovery. 6

Manage Mirtazapine-Related Weight Gain

Reduce mirtazapine from 30mg to 15mg or 7.5mg at bedtime, as lower doses provide better sleep benefits with less weight gain and appetite stimulation. 6, 5

• The American Academy of Family Physicians recommends that the most benefit for sleep comes at lower mirtazapine doses (7.5-15mg), while higher doses paradoxically cause more activation. 6
• Implement a gradual taper: reduce to 22.5mg for 1-2 weeks, then to 15mg for 2-4 weeks, assessing sleep quality and mood at each step. 6, 5
• If sleep remains adequate at 15mg but weight gain continues, consider further reduction to 7.5mg. 6
• Defer this change for 2-4 weeks until she is more settled in her residential program, as she wisely requested. 6, 5
• Monitor for SSRI discontinuation-like symptoms during taper (irritability, anxiety, dizziness, sensory disturbances) even though mirtazapine is not an SSRI. 6

Critical Safety Monitoring

Monitor for serotonin syndrome if adding an SSRI/SNRI to mirtazapine, and avoid combining with tramadol or other serotonergic agents. 5

• Signs include mental status changes, autonomic instability (tachycardia, labile blood pressure, hyperthermia), neuromuscular symptoms (tremor, rigidity, myoclonus), and GI symptoms. 5
• Avoid benzodiazepines entirely due to respiratory depression risk when combined with buprenorphine. 5
• Given her history of endocarditis, obtain baseline ECG before starting any new psychotropic medication, as mirtazapine can prolong QTc interval, particularly at higher doses. 5
• Monitor CBC periodically (every 3-6 months) given the rare but serious risk of agranulocytosis with mirtazapine. 5

Address Dental Needs Urgently

Refer immediately to dentistry for comprehensive evaluation and treatment planning, as her severe dental disease (edentulous maxilla, only 4 mandibular teeth) poses infection risk given her endocarditis history. 5

• Patients with history of endocarditis require antibiotic prophylaxis before dental procedures.
• Poor dentition can contribute to chronic pain, nutritional deficiencies, and increased infection risk.
• Coordinate with her residential program to ensure dental care is prioritized.

Contraception Continuation

Continue norethindrone oral contraceptive as prescribed, ensuring adherence is monitored given her complex medication regimen. 5

• Buprenorphine does not significantly interact with hormonal contraceptives.
• Reliable contraception is essential given teratogenic concerns with multiple medications and the need for stability during recovery.

Avoid Common Pitfalls

• Never abruptly discontinue mirtazapine—taper by approximately 10% per week to minimize withdrawal symptoms. 3, 6
• Do not prescribe NSAIDs for more than 1-2 days due to her documented rash reaction. 5
• Never add benzodiazepines despite anxiety complaints—the combination with buprenorphine significantly increases overdose risk. 5
• Do not reduce or discontinue Sublocade while she remains stable—premature discontinuation increases relapse risk substantially. 2
• Avoid prescribing mixed agonist-antagonist opioids (pentazocine, nalbuphine, butorphanol) as they may precipitate withdrawal in patients on buprenorphine. 3

Long-Term Discontinuation Planning

When the patient achieves sustained stability (minimum 12-24 months), consider transitioning to Sublocade 100mg monthly for 2-3 months before discontinuation to minimize withdrawal symptoms. 7

• A single 100mg injection of extended-release buprenorphine can facilitate final discontinuation by providing a gradual taper with minimal withdrawal symptoms. 7
• Buprenorphine plasma concentrations decrease slowly after discontinuation of Sublocade, providing a built-in taper. 1
• Ensure robust psychosocial supports, stable housing, employment, and mental health treatment are in place before attempting discontinuation. 2