This handout is for clonidine / α2-agonist withdrawal hypertensive crisis (rebound ne surge htn + tachy + diaphoresis + tremor 18-72 h after abrupt cessation of clonidine, methyldopa, dexmedetomidine, or guanfacine). Your care team identified this based on: abrupt cessation (or major dose reduction) of clonidine, methyldopa, dexmedetomidine, guanfacine, or tizanidine within last 18-72 h + sbp ≥180 / dbp ≥120 (reid lancet 1986 pmid 2867300).
Other reasons your team may use this plan: htn + tachycardia + diaphoresis + tremor + agitation + headache + insomnia 18-72 h after missed clonidine doses — classic rebound syndrome (hansson 1980; reid 1986); clonidine transdermal patch failure (detached, removed, expired without replacement) — depot effect delays withdrawal onset to 24-72 h after patch loss.
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| clonidine | 0.1-0.3 mg PO loading dose, then 0.1-0.2 mg PO q6-8h titrate (or restart home dose); transdermal Catapres-TTS-3 patch 0.3 mg/24h × 7 d MAX | PO + transdermal | q6-8h PO + weekly patch | Reid Lancet 1986 PMID 2867300 — resumption of α2-agonist restores central inhibition + reverses rebound NE surge; transdermal patch provides sustained release (2-3 d onset due to depot effect, bridge with PO) |
| labetalol | 10-20 mg IV q10 min titrate to SBP <160 (max 300 mg cumulative), OR infusion 0.5-2 mg/min | IV | PRN bolus or continuous | Mixed α/β safe in clonidine withdrawal (different from cocaine — resumed α2-agonist restores central inhibition so β-blockade does not produce same unopposed-alpha problem); standard HTN-emergency agent per AHA 2025 |
| phentolamine | 1-5 mg IV q5-15 min titrate | IV | PRN bolus | Pure alpha-blocker reverses rebound NE-driven alpha-vasoconstriction; rescue if concurrent β-blocker therapy worsens rebound |
| nitroglycerin | 5-200 mcg/min IV titrate q3-5 min | IV | continuous | Vasodilator + coronary vasodilator; useful if pulmonary edema from acute LV strain |
| lorazepam | 0.5-1 mg IV q4-6h PRN | IV | PRN | Symptomatic relief of rebound features (tremor + agitation + insomnia); not the primary anti-HTN agent here |
| methyldopa | 250-500 mg PO BID-TID | PO | BID-TID | Alternative central α2-agonist if clonidine unavailable; preferred in pregnancy (long safety record) |
| AVOID isolated β-blocker without α-blockade or clonidine resumption | AVOID | N/A | N/A | Same unopposed-alpha pharmacological principle as cocaine + pheochromocytoma — isolated β-blockade leaves alpha-vasoconstriction unopposed → worsens HTN; mixed α/β labetalol is safe here because clonidine resumption restores central inhibition |
| GRADUAL TAPER over 7-14 d if discontinuing clonidine | 0.3 mg → 0.2 mg × 3 d → 0.1 mg × 3 d → 0.05 mg × 3 d → off | PO | graduated reduction | Reid Lancet 1986 PMID 2867300 — taper over 7-14 d minimizes rebound risk; consider introducing alternative HTN regimen (ACEi/ARB + CCB) before taper to maintain BP control |
| PERIOPERATIVE PROTOCOL — continue clonidine peri-op or convert to transdermal patch 24-48 h pre-op | Catapres-TTS-3 patch 0.3 mg/24h placed 24-48 h pre-op | transdermal | weekly | Garbus Anesthesiology 1979 — transdermal patch maintains drug levels during NPO + surgery; preventing perioperative withdrawal crisis |
Plan: Clonidine / α2-agonist withdrawal HTN crisis — RESUME CLONIDINE first (PO + transdermal patch for sustained), IV labetalol bridge, phentolamine for severe, AVOID isolated β-blocker, perioperative protocol + adherence counseling for prevention
Contact your care team if any of the following happen:
Call 911 or go to the nearest emergency room right away if you have:
CRITICAL ADHERENCE COUNSELING + medication-card warning ("Do not stop clonidine abruptly — taper over 7-14 d if discontinuing"); MEDICALERT BRACELET if recurrent events; if patient continues clonidine — establish reliable refill system + advance-supply (90-day fill); if patient discontinuing clonidine — gradual taper over 7-14 d (e.g., 0.3 mg → 0.2 mg × 3 d → 0.1 mg × 3 d → 0.05 mg × 3 d → off); PERIOPERATIVE PROTOCOL — continue clonidine perioperatively OR convert to transdermal Catapres-TTS-3 patch 24-48 h pre-op (Garbus Anesthesiology 1979); transition to alternative HTN regimen with appropriate titration if discontinuing (e.g., introduce ACEi/ARB + CCB before clonidine taper); psychiatric/substance use evaluation if recurrent events suggest deeper issue; PCP + cardiology follow-up within 1-2 weeks
Guideline: 2025 ACC/AHA HTN Guideline (Whelton) + Reid Lancet 1986 PMID 2867300 (clonidine withdrawal syndrome comprehensive review) + Garbus Anesthesiology 1979 (perioperative protocol)