Dipyrone |
Analgesic Antipyretic |
Pro-drug metabolized in the gastrointestinal tract. (57) Major active metabolite: 4-MAA. (54,57) Bioavailability of 4-MAA: 89% for the solution formulation (pretty close to that of the intravenous and intramuscular routes). (54,57) No food-drug interactions. (57) Plasma half-life of 4-MAA: 2.70.5 hours. (57) Excretion: 96% in urine and 6% in feces (57)
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The metabolite 4-MAA is mainly responsible for clinical effects. (57) Onset of antipyretic action: 30 to 60 minutes. (57) Approximate duration of action: 4 hours (57)
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Peripheral action: reversible inhibition of prostaglandin synthesis, mainly PGE2, by inhibiting COX-1, COX-2 and possibly COX-3, although evidence still not clear. (54,57,60) Central action: inhibition of COX-1 and prostaglandin synthesis in the central nervous system, including PGE2, a primary fever mediator also produced in the hypothalamic regulatory center after stimulation of endogenous and exogenous pyrogens (57,61)
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From 3 months and over 5kg (52)
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Hypersensitivity to the pyrazolone class Diseases of the hematopoietic system Severe allergic reactions to other analgesics Porphyria or G6PD deficiency |
Anaphylactic shock, Stevens-Johnson syndrome, agranulocytosis (rare, but may last for up to 1 week), pancytopenia, hypotension and urinary retention |
Dosing: 10-16mg/kg. (52) * Intervals: 6-8 hours. (49,52) Maximum daily dose: limit 4 doses (52)
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Drops: 500mg/mL. (1 drop = 25mg). Oral solution: 50mg/mL. Injectable (IM/IV): 500mg/mL. Suppositories: 300mg |
Ibuprofen |
Mild to moderate pain Fever |
Racemic mixture: inactive R isomer is converted into active S isomer Bioavailability: 80%-85%. (58,62) Reduced absorption in the presence of food. (58) Plasma half-life: 1- 3 hours. (61,62) Excretion: mainly urinary (58)
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Pharmacologically active isomer is S. Onset of antipyretic action: 15-30 minutes. (58) Studies have shown the antipyretic effect may be slower than the analgesic effect, and vary according to the age group of the child (faster in ≤1 year-old). (62) Approximate duration of action: 4-6 hours (58)
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Peripheral action: reversible inhibition of prostaglandin synthesis, including PGE2, by inhibiting COX-1 and possibly COX-2. (8,10) Other mechanisms proposed, although not fully elucidated: chemotaxis inhibition, changes in lymphocyte activity, platelet aggregation inhibition, activation of neutrophils and decreased levels of pro-inflammatory cytokines. (58)
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From 6 months and over 5kg (58)
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Hypersensitivity to ibuprofen. Active peptic ulcer or gastrointestinal bleeding Children with history of asthma, rhinitis, urticaria, nasal polyp, angioedema, bronchospasm and other symptoms of allergic or anaphylactic reaction triggered by nonsteroidal anti-inflammatory drugs |
Headache, dizziness, edema, gastric intolerance, nausea, constipation or diarrhea, pruritus, rash, bruising |
Dosing: 5-10mg/kg. (58) Intervals 6- 8 hours. (58) Maximum daily dose: 40mg/kg/day (limit 200mg/ dose and 800mg/day) (58)
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Oral suspension (drops): 50mg/mL. (1 drop = 5mg). Oral suspension (drops): 100mg/mL. (1 drop = 10mg). Oral suspension: 30mg/mL. |
Acetaminophen |
Mild to moderate pain Fever |
Bioavailability: 85%-98%. (59) Slower absorption in the presence of food. (59) Metabolized mainly by the liver (conjugation and oxidation via cytochrome P450 system). (59) Plasma half-life in children: 1,5-3 hours (approximately 1 hour longer in newborns). (59) Excretion: urinary, mainly in the form of metabolites (59)
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Onset of antipyretic action: 15-30 minutes. (59) Approximate duration of action: 4-6 hours (59)
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Peripheral action: reversible inhibition of prostaglandin synthesis (including PGE2), mainly through COX-2 enzyme inhibition, but with milder action than selective inhibitors. (63) Central action: direct effect on the hypothalamic regulatory center (59,64)
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From newborns and over 3kg (58)
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Hypersensitivity to acetaminophen In moderate renal failure, maximum frequency is every 6 hours. In severe renal failure, maximum frequency is every 8 hours |
Hepatotoxic with overdoses or prolonged use of high doses |
Dosing: 10-15mg/kg. (59,64) Intervals: 4-6 hours. (59,64) Maximum daily dose: 50-75mg/kg (limit of 5 doses). (59,64) Many children or young people with severe diseases have low weight for age. The doses described here are calculated considering mainly weight, not age, to minimize the risk of overdose per age group |
Oral solution (drops) 200mg/mL. (1 drop = 13.3mg). Oral suspension: 100mg/mL. Oral suspension: 32mg/mL. Chewable tablets: 160mg |