Antipyretic, Articles, Drug Classes, Medical Emergencies, Nervous System Emergencies, Pharm
🧊 Antipyretics – EMS Drug Class Overview
01
Apr
Apr
Introduction to Antipyretics
Antipyretics are medications used to reduce fever by acting on the body’s internal thermostat. In EMS, they are most commonly used for pediatric fevers, febrile illness, and systemic infections like sepsis. The primary EMS antipyretics are acetaminophen and ibuprofen, while some systems also include ketorolac. Aspirin has antipyretic effects but is rarely used for that purpose in modern EMS.
📋 Quick Reference: Antipyretics at a Glance
| Feature | Info |
|---|---|
| Mechanism | Inhibits prostaglandin-mediated hypothalamic temperature elevation |
| Main EMS Uses | Pediatric fever, febrile illness, supportive sepsis care |
| Onset/Duration | Onset: 15–30 min · Peak: 1–2 hrs · Duration: 4–6 hrs |
| Watch out for | Liver toxicity (acetaminophen), GI bleeding (NSAIDs), Reye’s syndrome (aspirin) |
| Common EMS Drugs | Acetaminophen, Ibuprofen (some protocols: Ketorolac, Aspirin) |
🔑 Key Takeaways
- ✅ Antipyretics are frequently used in EMS for fever control, especially in children and sepsis.
- ✅ Acetaminophen is the safest and most commonly used option.
- ⚠️ Ketorolac and Aspirin have antipyretic properties but are not first-line in most EMS protocols.
- 🔁 Antipyretics often overlap with analgesics and NSAIDs.
- 🚑 Local protocols vary—always check your regional guidelines.
🧬 Mechanism of Action
Antipyretics reduce fever by inhibiting prostaglandin production in the hypothalamus, which lowers the body’s internal “set point.” This leads to heat loss through vasodilation and sweating.
- Acetaminophen: Acts centrally in the CNS.
- NSAIDs (Ibuprofen, Ketorolac, Aspirin): Act centrally and peripherally by inhibiting COX enzymes.
🩺 Common Indications in EMS
- Febrile pediatric patients (with or without seizure activity)
- Systemic infections (e.g., sepsis)
- Hyperthermia with altered mentation
- General fever-related discomfort
- Heat illness
⚠️ Contraindications / Cautions
| Drug | Contraindications |
|---|---|
| Acetaminophen | Liver disease, known hypersensitivity |
| Ibuprofen | GI bleeding, renal impairment, trauma |
| Ketorolac | Bleeding disorders, recent surgery, kidney disease |
| Aspirin | Pediatric patients (Reye’s syndrome), GI ulcers, active bleeding |
⚠️ Note: Aspirin and Ketorolac are not first-line fever reducers in EMS. Their use depends on local protocols and clinical judgment.
💊 Common EMS Antipyretics
| Generic Name | Trade Name(s) | EMS Notes |
|---|---|---|
| Acetaminophen | Tylenol, Ofirmev | Preferred agent. Available PO and IV. Safe and effective. |
| Ibuprofen | Motrin, Advil | Effective NSAID. PO only. Avoid in trauma. |
| Ketorolac | Toradol | NSAID used for pain; some protocols use for fever. Injectable. |
| Aspirin | ASA | Rarely used as antipyretic. Primary EMS use is antiplatelet. |
📏 Dosing Considerations
| Drug | Route | Adult Dose | Pediatric Dose |
|---|---|---|---|
| Acetaminophen | PO/IV | 650–1000 mg | 15 mg/kg |
| Ibuprofen | PO | 400–800 mg | 10 mg/kg |
| Ketorolac | IM/IV | 15–30 mg | Not typical |
| Aspirin | PO | 325–650 mg | Contraindicated in children |
👶 Special Considerations
- Pregnancy: Acetaminophen is safest; avoid NSAIDs in 3rd trimester.
- Pediatrics: Use acetaminophen and ibuprofen. Avoid aspirin due to Reye’s syndrome risk.
- Elderly: Use caution with NSAIDs due to renal and GI concerns.
- Overdose Risks: Acetaminophen overdose is a leading cause of acute liver failure and requires N-acetylcysteine (NAC) as an antidote.
🔁 Related Drug Classes
- NSAIDs – Includes ibuprofen, ketorolac, aspirin.
- Analgesics – Many antipyretics also relieve pain.
- Non-opioid Analgesics – Overlaps with antipyretic medications in action and use.
🚑 Associated Conditions
- Fever
- Febrile Seizures
- Sepsis
- Heatstroke / Hyperthermia
📚 References
- DailyMed: https://dailymed.nlm.nih.gov
- MedlinePlus Drug Info: https://medlineplus.gov
- PEPP, AHA PALS, and select regional protocols
