Is it safe to add Buspar (buspirone) and Hydroxyzine to the medication regimen of an adult patient with a history of anxiety or depression and gastrointestinal issues, who is currently taking Lexapro (escitalopram) 15mg, Bentyl (dicyclomine) for abdominal pain, and Lunesta (eszopiclone) PRN at night?

Safety of Adding Buspar and Hydroxyzine to Current Regimen

Yes, it is safe to add both buspirone (Buspar) and hydroxyzine to this patient's current regimen of Lexapro 15mg, Bentyl, and Lunesta PRN, but you must monitor closely for serotonin syndrome given the combination of serotonergic agents.

Critical Safety Consideration: Serotonin Syndrome Risk

The primary concern is serotonin syndrome when combining buspirone with escitalopram (Lexapro), as both have serotonergic activity 1. The FDA drug label for buspirone explicitly warns that "the development of a potentially life-threatening serotonin syndrome has been reported with SNRIs, SSRIs, and other serotonergic drugs, including buspirone, alone but particularly with concomitant use of other serotonergic drugs" 1.

Monitor for These Serotonin Syndrome Symptoms:

• Mental status changes (agitation, confusion, delirium) 1
• Autonomic instability (tachycardia, labile blood pressure, diaphoresis, flushing, hyperthermia) 1
• Neuromuscular changes (tremor, rigidity, myoclonus, hyperreflexia, incoordination) 1
• Gastrointestinal symptoms (nausea, vomiting, diarrhea) 1

Case report evidence confirms this risk: A 37-year-old patient developed confusion, diaphoresis, incoordination, diarrhea, and myoclonus after buspirone was added to fluoxetine 2.

Drug-Specific Safety Profile

Buspirone with Current Medications:

With Lexapro (Escitalopram):

• The combination is used clinically but requires careful observation 1
• Start buspirone at low doses (5 mg twice daily initially) and titrate slowly 3
• Maximum dose typically 20 mg three times daily 3
• Benefits may take 2-4 weeks to manifest 3, 4

With Bentyl (Dicyclomine):

• No significant interaction expected
• Both can cause anticholinergic effects, but buspirone has minimal anticholinergic activity 5

With Lunesta (Eszopiclone):

• No direct contraindication 1
• Buspirone causes minimal sedation compared to benzodiazepines 5
• Monitor for additive sedation when Lunesta is used 3

Hydroxyzine with Current Medications:

With Lexapro:

• No serotonin syndrome risk as hydroxyzine is an antihistamine, not serotonergic 3, 6
• Safe combination for anxiety management 7

With Bentyl:

• Both have anticholinergic properties; monitor for dry mouth, constipation, urinary retention 3

With Lunesta:

• This is the most significant concern: Both are sedating agents 3
• The FDA has issued a black box warning about combining sedating medications, particularly opioids with benzodiazepines, warning of "slowed or difficult breathing and death" 3
• While this warning specifically addresses opioids, caution is warranted with any sedating combination
• Advise patient to use Lunesta only when truly needed and avoid taking it on the same night as hydroxyzine if possible 3

With Buspirone:

• Evidence shows hydroxyzine and buspirone can be used together safely 7
• A multicenter trial of 244 patients demonstrated both drugs were well-tolerated when compared to placebo 7

Clinical Efficacy Supporting This Combination

For Anxiety and Gastrointestinal Symptoms:

Buspirone:

• Effective for generalized anxiety disorder with efficacy comparable to benzodiazepines 5, 7
• May be useful for mild to moderate agitation in patients with GI issues 3
• Lacks abuse potential, dependence, and withdrawal symptoms 5
• Can be used in IBS patients with anxiety without depression 4

Hydroxyzine:

• More effective than placebo for generalized anxiety disorder (OR 0.30,95% CI 0.15 to 0.58) 6
• Equivalent efficacy to buspirone in head-to-head comparison 7
• Useful for anxiety in patients with abdominal pain 3
• Can be administered orally or intramuscularly 3

For Abdominal Pain Context:

The combination of SSRIs (like Lexapro) with anxiolytics is supported for patients with IBS and anxiety 3. SSRIs at therapeutic doses are recommended as first-line treatment when mood disorders are suspected alongside GI symptoms 3. Adding buspirone for anxiety augmentation is a recognized strategy 3.

Practical Implementation Algorithm

Starting Buspirone:

1. Begin with 5 mg twice daily (morning and midday) 3
2. Increase by 5 mg every 5-7 days as tolerated 3
3. Target dose: 10-20 mg three times daily 3
4. Warn patient about initial anxiety or sleep disturbance in first 10 days 4
5. Therapeutic benefit expected in 2-4 weeks 3, 4

Starting Hydroxyzine:

1. Begin with 12.5 mg twice daily and 25 mg at bedtime 7
2. Can be used PRN for breakthrough anxiety 3
3. Primary side effect is drowsiness/sleepiness 6, 7
4. Avoid concurrent use with Lunesta on the same night 3

Monitoring Schedule:

• Week 1: Contact patient to assess for serotonin syndrome symptoms 1
• Week 2-4: Monitor for therapeutic benefit and side effects 3, 4
• Ongoing: Assess for excessive sedation, anticholinergic effects, and medication efficacy 3, 6

Common Pitfalls to Avoid

1. Do not combine buspirone with MAOIs - this is an absolute contraindication 1
2. Do not use benzodiazepines long-term - if patient requests these instead, explain that buspirone/hydroxyzine have better safety profiles without dependence risk 3, 5
3. Do not expect immediate results from buspirone - set realistic expectations of 2-4 week onset 3, 4
4. Do not ignore sedation - excessive sedation can precede respiratory depression, particularly with multiple sedating agents 3
5. Do not discontinue buspirone abruptly if serotonin syndrome develops - taper over 10-14 days to avoid withdrawal 3