Dosing and uses of Alka Seltzer Original (aspirin/citric acid/sodium bicarbonate)
Adult dosage forms and strengths
aspirin/citric acid/sodium bicarbonate
effervescent tablet
- 325mg/1000mg/1916mg
Antacid & Analgesic
Indicated for heartburn, acid indigestion, and sour stomach when accompanied with headache or body aches
2 tablets (dissolved in water) PO q4hr PRN; not to exceed 8 tablets/day (see Administration)
Age >60 years old: Do not exceed 4 tablets/day (see Cautions)
Pediatric dosage forms and strengths
aspirin/citric acid/sodium bicarbonate
effervescent tablet
- 325mg/1000mg/1916mg
Antacid & Analgesia
<12 years old: Safety and efficacy not established
≥12 years: As adults; 2 tablets (dissolved in water) PO q4hr PRN; not to exceed 8 tablets/day (see Administration)
Alka Seltzer Original (aspirin/citric acid/sodium bicarbonate) adverse (side) effects
Frequency not defined
Flatulence
Rebound hyperacidity
Stomach cramps
Vomiting
Warnings
Contraindications
Hypocalcemia, hypochloremia, respiratory alkalosis
Hypersensitivity to aspirin or any component
Cautions
History of: CHF, renal impairment, hypertension
Use of salicylates in pediatric patients with varicella or influenza-like illness is associated with increased incidence of Reye Syndrome
Bleeding risk
- Higher doses or use for a longer period than recommended increases risk of serious bleeding
- Risk increased with ≥1 of the following
- Age ≥60 yr
- History of stomach ulcers or bleeding problems
- Coadministration or anticoagulant or corticosteroids
- Coadministration with other NSAIDs Consumes ≥3 alcoholic drinks every day
Pregnancy and lactation
Pregnancy category: C
Lactation: unknown
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Alka Seltzer Original (aspirin/citric acid/sodium bicarbonate)
Mechanism of action
Gastric acid neutralization and analgesia by inhibiting prostaglandin synthesis by cyclooxygenase
Pharmacokinetics
Onset: PO, as antacid: 15 min
Duration: PO: 1-3 hr
Bioavailability: 4-45%, food increases absorption 10-30%
Protein Bound: 45%
Metabolism: in the presence of stomach acid, bicarbonate ion forms carbon dioxide and water, sodium and excess bicarbonate are absorbed into plasma
Excretion: reabsorbed by kidney, <1% excreted in urine
Administration
Oral Administration
Fully dissolve 2 tablets in 4 oz of water before orally ingesting
