Acupan 20mg/2ml solution for injection is a prescription-only, centrally acting, non-opioid analgesic containing the active ingredient nefopam hydrochloride. This specific pack size contains 5 glass ampoules, each loaded with 2ml of solution.
It is used primarily for the short-term symptomatic relief of acute painful conditions, most notably postoperative pain following surgery. Unlike morphine, Acupan is a non-morphinic agent, meaning it does not cause respiratory depression or slow down intestinal transit. However, a risk of drug dependency does exist, and it is strictly contraindicated for chronic pain management.
Clinical Overview & Mechanics
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Active Composition: Each 2 ml glass ampoule contains 20 mg of nefopam hydrochloride. Excipients include disodium phosphate, sodium phosphate, and water for injection.
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Mechanism of Action: Nefopam works within the central nervous system by inhibiting the reuptake of catecholamines (dopamine, norepinephrine) and serotonin. It also features unique anti-hyperalgesic properties and helps mitigate post-operative shivering/chills.
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Key Distinctions: It is completely unrelated to traditional NSAIDs or opioid medications. Because it is distinct from opioids, a sudden switch from morphine to Acupan in opioid-dependent individuals can trigger an acute withdrawal syndrome.
Administration & Dosage Protocols
Acupan must be administered by a trained healthcare professional using one of two distinct clinical pathways:
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Intramuscular (IM) Route: Administered via a deep intramuscular injection. The standard dosage is 20 mg per injection. If clinical pain persists, it may be repeated every 6 hours as needed. The total daily dose must never exceed 120 mg in a 24-hour period.
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Intravenous (IV) Route: Administered strictly via a slow intravenous infusion lasting at least 15 minutes. The injection can be diluted using standard perfusion fluids like isotonic sodium chloride (saline) or glucose/dextrose solution. It can be repeated every 4 hours if necessary, keeping within the 120 mg daily ceiling.
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Critical Protocol: The patient must remain completely flat on their back (recumbent position) during and for 15 to 20 minutes after IV or IM administration to safely prevent orthostatic side effects like severe dizziness, nausea, or fainting.
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Mixing Restriction: Medical personnel should avoid mixing Acupan with any other injectable medications in the same syringe or infusion setup.
Absolute Contraindications
This medication must not be administered under any circumstances to individuals presenting with:
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Age Limits: Children and teenagers under the age of 15.
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Hypersensitivity: A known allergy or hypersensitivity to nefopam hydrochloride or the phosphate-based excipients.
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Neurological History: Active convulsions or a documented prior history of seizure disorders.
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Urological Risks: A high risk of urinary retention stemming from urethroprostatic or prostate-related clinical conditions.
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Ocular Risks: A risk of acute angle-closure glaucoma (severe pressure buildup inside the eye structures).
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Cardiovascular History: Recent myocardial infarction (heart attack). Concurrent use with Monoamine Oxidase Inhibitors (MAOIs) is also contraindicated.
Side Effects & Clinical Cautions
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Common Side Effects: Dizziness, significant sweating, nausea, vomiting, drowsiness, and dry mouth.
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Anticholinergic & Sympathomimetic Responses: Can cause tachycardia (elevated heart rate), palpitations, blurred vision, and urinary retention.
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Special Precautions: Extreme caution and dosage adjustments are required for individuals suffering from hepatic (liver) insufficiency or renal (kidney) impairment due to the increased threat of drug accumulation. Due to its severe heart-accelerating and anticholinergic profiles, it is generally discouraged for elderly populations and those with advanced cardiovascular disease.
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Substance Interactions: Alcohol must be completely avoided during treatment, as it drastically amplifies the sedative and central nervous system side effects of the medication.
