(acetaminophen, APAP, paracetamol)

Brands

Tylenol Tablets, Children’s Tylenol Suspension, Children / Infant’s Tylenol Concentrated Drops

Availability

• Tablets: 325 mg, 500 mg
• Capsules: 325 mg, 500 mg
• Oral drops: 80 mg/mL
• Oral liquid: 160 mg/mL
• Oral Elixer: 160 mg/5 mL
• Oral solution: 80 mg/mL
• Oral syrup: 160 mg/5mL

Pharmacology

Acetaminophen, a phenol derivative, is both analgesic and antipyretic. It inhibits the synthesis of prostaglandins that sensitize pain receptors to stimulation. Unlike aspirin it is not an anti-inflammatory agent.

This drug is both rapidly and completely absorbed and is widely distributed into the tissues, crossing the placenta and distributed in breast milk in small amounts.

Studies in rats have shown that acetaminophen may cause reduced fertility in both males and females, as well as, organogenesis, fetotoxicity, and areas of necrosis in both the liver and kidney of pregnant rats and fetuses at greater than human dosing. At this time, it is advised to refrain from use in pregnant and nursing rats, unless benefit outweighs risk as assessed by veterinarian.

Acetaminophen is mostly excreted in urine.

Indications

Used for temporary relief of minor pain.

Drug Interactions or Contraindications

• Not recommended to be used post-op in animals having received Halothane.
• Concurrent use with loop diuretics such as furosemide may increase the risk of ototoxicity.
• Do not use in renal or hepatic diseases.

Adverse Reactions

Skin: itching

GU: analgesic nephrotoxicity

Hepatic: long term use or single high dose can lead to toxicity resulting in renal insufficiency and liver failure.

Renal: studies in rats have shown tubular necrosis with high dosages.

Dosage Recommendations

Recommended method :Children’s Tylenol= 1 mg/mL to 2 mg/mL in drinking water (based on 100mL of drinking water). ^{1, 26, 34, 41, 42, 44}

or

100 mg/kg to 300 mg/kg, PO (oral), q4hr  ¹⁹

or

100 mg/kg, PO  ^41, 44

or

200 mg/kg, PO  ^34, 41, 44

Considerations

• For short term use only. If used repeatedly, use a decreased dosage.
• ALERT: Always verify drug concentrations when calculating dose. If using the following remember: Infants’ Tylenol Concentrated Drops has a higher concentration of drug per mL than does Children’s Strength Tylenol Suspension.
• Store drug at room temperature.