Demerol 100mg is a brand name for meperidine hydrochloride, a synthetic opioid analgesic (painkiller) from the phenylpiperidine class. The 100 mg dose refers to a common tablet, injection, or syrup strength used for moderate to severe pain relief. It’s a Schedule II controlled substance in the US due to high abuse potential and risk of addiction.

Primary Uses (FDA-approved):

• Short-term management of moderate-to-severe acute pain (e.g., post-surgery, injury).
• Sometimes as a premedication for anesthesia or for labor pain (though less common now due to safer alternatives).
• Not recommended for chronic pain due to risks like tolerance buildup and toxicity from a metabolite called normeperidine.

How it Works:

• Acts as a mu-opioid receptor agonist in the central nervous system, blocking pain signals and producing euphoria/sedation.
• Onset: 15-30 minutes (oral); peak effect: 1-2 hours; duration: 2-4 hours.
• Half-life: ~2-5 hours (longer in elderly/renal impairment).

Dosage Guidelines (Adults, per standard medical references like Lexicomp/UpToDate):

Always follow prescriber instructions; do not self-adjust.

Common Side Effects:

• Mild: Drowsiness, dizziness, nausea, constipation, sweating.
• Serious: Respiratory depression, low blood pressure, seizures (from normeperidine, especially >48 hrs use), serotonin syndrome (if combined with SSRIs/MAOIs).

Warnings & Risks (Black Box from FDA):

• Overdose: Can cause coma, respiratory arrest—naloxone reverses it.
• Addiction/Withdrawal: High risk; avoid abrupt stop after prolonged use.
• Contraindications: Avoid with MAOIs (within 14 days), severe respiratory issues, acute asthma, paralytic ileus.
• Drug Interactions: Potentiates CNS depressants (alcohol, benzos, other opioids); risk of QT prolongation.
• Pregnancy: Category C; use only if benefits outweigh risks (neonatal withdrawal possible).

Evidence & Facts:

• Efficacy: Effective for acute pain per Cochrane reviews, but inferior to morphine for severe pain and riskier long-term (normeperidine toxicity documented in studies like NEJM 1980s cases).
• Decline in Use: CDC guidelines (2022) favor non-opioids first; meperidine use dropped 90% in hospitals since 2000s due to safer options like morphine/hydromorphone.
• Street Value/Abuse: ~$1-5 per 100 mg pill (DEA data); often diverted for euphoria.

This is not medical advice—consult a doctor/pharmacist for personal use. If experiencing overdose (slow breathing, unresponsiveness), call emergency services immediately.