Catapres Injection (Clonidine Hydrochloride)
Compared with: Blackmores Conceive Well Gold 28 Tablets + 28 Capsules

Catapres Injection (Clonidine HCl 150 µg/mL) is a centrally acting α₂‑adrenergic agonist indicated for hypertensive crises and perioperative hypertension. By reducing sympathetic outflow from the brainstem, it produces rapid vasodilation and blood‑pressure control when administered IV at 0.2–0.5 µg/kg/min
Medsafe

Clonidine Hydrochloride – 150 µg per mL sterile aqueous solution

Clonidine IV/IM Injection

Catapres® Ampoules

α₂‑Adrenergic Agonist Injection

Kapvay® (oral for ADHD; different formulation)
Clonidine binds to presynaptic α₂A‑adrenergic receptors in the locus coeruleus and medullary vasomotor center, inhibiting norepinephrine release. This central sympatholysis leads to:

Decreased Heart Rate and Cardiac Output

Peripheral Vasodilation

Reduced Renin Secretion

Overall, systemic vascular resistance and blood pressure fall rapidly with intravenous or intramuscular administration
Hypertensive Emergency / Crisis: Rapid‑acting control of severe hypertension in critical care settings
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Perioperative Hypertension: Management of intraoperative or postoperative blood‑pressure spikes

Adjunct in Surgical Anaesthesia: To reduce anesthetic requirements and facilitate hemodynamic stability

Off‑Label: Management of withdrawal syndromes (e.g., alcohol, opioid) and refractory pain via epidural infusion (specialist use)
Indication Dose Route Notes
Hypertensive Crisis 0.2 µg/kg/min IV infusion, titrate to effect IV infusion Do not exceed 0.5 µg/kg/min to avoid paradoxical BP rise; max 0.15 mg per infusion
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IM Injection 75–150 µg per dose IM injection Use when IV access is unavailable; repeat up to four times daily
Perioperative Control 5–10 µg/kg bolus; follow with IV infusion 0.1 µg/kg/min IV bolus + infusion Administer slowly over 5 minutes for bolus; monitor hemodynamics
Epidural Infusion (Off‑Label) 30 µg/hr initial, titrate to 40 µg/hr max Epidural infusion Specialist administration; monitor for hypotension and bradycardia

Preparation: Inspect ampoule; draw up with sterile technique. For infusion, dilute in ≥50 mL of 0.9 % sodium chloride.

Monitoring: Continuous blood‑pressure and heart‑rate monitoring required; adjust rate to maintain target BP.
Formulation: Aqueous solution in 1 mL ampoules (150 µg/mL)

Route: Intravenous (preferred), Intramuscular, Epidural (off‑label)

Legal Status: Prescription Only Medicine (Rx‑only)
Pregnancy & Breastfeeding: Use only if benefit justifies potential risk; limited human data.

Renal / Hepatic Impairment: No specific dose adjustment data; monitor clinical response closely.

Pediatric: IV use in very low birth‑weight neonates for anesthesia adjunct—expert consultation required.

Elderly: Increased sensitivity—start at lower infusion rates and titrate slowly.
Hypotension, bradycardia

Dry mouth, sedation

Dizziness, headache
Rebound hypertension on abrupt withdrawal

Severe bradycardia or heart block

Central nervous system depression (somnolence, coma)

Paradoxical hypertension if infused too rapidly

Respiratory depression at high doses

Rebound Hypertension: Taper infusion gradually over 2–4 hours to prevent severe rebound ﹘ do not discontinue abruptly
Hypotension / Bradycardia: Prepare atropine for symptomatic bradycardia; ensure IV fluids ready to correct hypotension.

Paradoxical Response: Infusion rates >0.5 µg/kg/min can cause transient sympathoexcitation and BP spike.

CNS Depression: Use caution in patients with compromised airway or neurological status.

Drug Handling: Store ampoules at 2–8 °C; protect from light; use immediately after opening.
Therapeutic Class: Antihypertensive

Pharmacologic Class: Centrally Acting α₂‑Adrenergic Agonist

Legal Category: Prescription Only
Other Antihypertensives: Additive hypotension—reduce doses accordingly.

CNS Depressants (opioids, benzodiazepines): Enhanced sedation and respiratory depression—monitor respiratory rate.

Tricyclic Antidepressants: May antagonise clonidine’s antihypertensive effect—monitor BP.

Beta‑Blockers: Combined use increases risk of bradycardia and AV block—monitor ECG.

Sympathomimetics: May reduce efficacy; avoid concomitant use where possible.
Medsafe NZ Data (2017): IV infusion at 0.2 µg/kg/min controls hypertensive crises with onset <30 minutes and significant BP reduction within 2 hours

FDA Label (2009): Demonstrates clonidine’s half‑life 12–16 hours, onset 30–60 minutes, justifying continuous infusion protocols for stable control

FAQs – Catapres® Injection (Clonidine HCl)
Q1. How quickly does Catapres Injection lower blood pressure?
A: IV infusion produces significant BP reduction within 15–30 minutes; peak effect at 2 hours
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Q2. Can I use Catapres Injection for chronic hypertension?
A: No. It’s reserved for acute or perioperative settings—use oral clonidine or other antihypertensives for maintenance.

Q3. What if the infusion rate is too high?
A: May cause paradoxical hypertension and reflex tachycardia—reduce rate immediately and monitor.

Q4. How do I prevent rebound hypertension?
A: Gradually taper infusion over 2–4 hours before discontinuation
Q5. Can Catapres Injection be given IM?
A: Yes. IM 75–150 µg doses may be used when IV access is unavailable; effect onset ~30 minutes.

Q6. Is monitoring required after administration?
A: Continuous BP, heart rate, and respiratory monitoring are essential throughout infusion and taper.

Q7. How should unused ampoules be stored?
A: Store sealed ampoules at 2–8 °C; use immediately after opening; discard unused.
Catapres Injection, Clonidine IV Infusion, Hypertensive Crisis Treatment, Centrally Acting Antihypertensive, α₂‑Agonist Injection, EZ Chemist, Clonidine HCl Ampoules, Perioperative Hypertension Management, Acute BP Control, ICU Clonidine Therapy