What to do if experiencing goosebumps after starting Effexor (venlafaxine) with no other side effects?

Goosebumps After Starting Effexor (Venlafaxine)

Goosebumps (piloerection) after starting venlafaxine is a benign noradrenergic side effect that typically does not require treatment discontinuation if no other concerning symptoms are present.

Understanding This Side Effect

• Venlafaxine causes noradrenergic activation through its dual mechanism as a serotonin-norepinephrine reuptake inhibitor (SNRI), which can manifest as piloerection (goosebumps), sweating, and other autonomic symptoms 1, 2, 3

• This is distinct from the more common side effects like nausea (most common), dizziness, sweating, dry mouth, and sedation that occur in clinical trials 2, 3

• The noradrenergic effects are dose-dependent, meaning they may intensify if the dose is increased 2, 3

What You Must Monitor For

Critical Warning Signs (Require Immediate Action)

• Blood pressure elevation: Venlafaxine causes dose-dependent hypertension in 3-5% at doses ≤200 mg/day, 7% at 201-300 mg/day, and 13% at >300 mg/day 2

  • Check blood pressure and pulse regularly, as sustained hypertension may require dose reduction or discontinuation 1, 4

• Cardiovascular symptoms: Monitor for palpitations, chest discomfort, or dizziness, as venlafaxine carries higher cardiovascular risk than SSRIs 4

• Serotonin syndrome features: If goosebumps are accompanied by hyperthermia, diaphoresis, agitation, tremor, or confusion, this constitutes a medical emergency 1

Other Concerning Symptoms to Watch

• Excessive sweating (diaphoresis): This is a well-recognized SNRI adverse effect through noradrenergic mechanisms 1

  • If sweating becomes problematic, consider dose reduction or switching to an SSRI with lower sweating profile 1

• Nausea: The most common side effect (6% discontinuation rate), though it typically resolves within 1-3 weeks 2

Management Algorithm

If Goosebumps Are Isolated (No Other Symptoms)

1. Continue current therapy with reassurance that this is a benign autonomic effect 2, 3
2. Monitor blood pressure and pulse at each visit, as noradrenergic effects can progress 1, 4
3. Observe for 2-4 weeks, as many initial side effects resolve with continued treatment 2

If Additional Noradrenergic Symptoms Develop

1. Consider dose reduction if symptoms are bothersome, as effects are dose-dependent 2, 3
2. Taper slowly if reducing dose to avoid discontinuation syndrome (sweating, headache, dizziness, electric shock sensations) 1

If Blood Pressure Becomes Elevated

1. Reduce venlafaxine dose or discontinue if hypertension is sustained 2, 4
2. Switch to an SSRI (sertraline or escitalopram preferred) which have lower cardiovascular risk 1, 4

If Symptoms Become Intolerable

1. Switch to mirtazapine (reduces SNRI-induced sweating through serotonin antagonism) or bupropion (minimal serotonergic effects) 1
2. Never switch abruptly, especially with venlafaxine which has high discontinuation syndrome risk due to short half-life (3-4 hours) 1, 3
3. Never combine with MAOIs due to serotonin syndrome risk 1

Common Pitfalls to Avoid

• Do not ignore isolated goosebumps as a harbinger of more serious noradrenergic effects: Always check blood pressure, as venlafaxine has higher cardiovascular risk than SSRIs 4

• Do not abruptly discontinue venlafaxine: Its short half-life (3-4 hours) makes it particularly prone to withdrawal symptoms including sweating, anxiety, and electric shock sensations 1, 3

• Do not assume all antidepressants have equal autonomic side effects: Venlafaxine has higher discontinuation rates due to adverse effects compared to SSRIs, and is more dangerous in overdose 4

• Do not overlook dose-dependent effects: If planning to increase the dose, counsel the patient that noradrenergic symptoms (including goosebumps, sweating, blood pressure elevation) will likely intensify 2, 3