Dosing and uses of Aspirin rectal
Adult dosage forms and strengths
suppository
- 60mg
- 120mg
- 200mg
- 300mg
- 600mg
Antipyretic/Analgesic
300-600 mg PR q4-6hr PRn
Administration
Patient should lie on left side with knees bent
Remove protective wrap before inserting
Gently insert tip into rectum with slight side-to-side movement (tip of suppository pointing toward navel)
Pediatric dosage forms and strengths
suppository
- 120mg
- 200mg
- 300mg
- 600mg
Antipyretic/Analgesic
<12 years: 10-15 mg/kg/dose PR q4-6hr; not to exceed 4 g/day
>12 years: As adults; 300-600 mg PR q4-6hr PRn
Geriatric Dosing
Antipyretic/Analgesic
- <12 years: 10-15 mg/kg/dose PR q4-6hr; not to exceed 4 g/day
- >12 years: As adults; 300-600 mg PR q4-6hr PRN
Renal Impairment
CrCl<10 mL: Not recommended
Hepatic Impairment
Not recommended
Administration
Patient should lie on left side with knees bent
Remove protective wrap before inserting
Gently insert tip into rectum with slight side-to-side movement (tip of suppository pointing toward navel)
Geriatric dosage forms and strengths
Antipyretic/Analgesic
Aspirin rectal adverse (side) effects
Frequency not defined
Common
- Rectal discomfort
- Tinnitus (high or chronic dose)
- Rash
- Urticaria
Angioedema
DIC
Hypotension
Tachycardia
CNS alteration
Dizziness
Headache
Dermatologic problems
Hives
Electrolyte disturbances; dehydration, hyperkalemia, metabolic acidosis, respiratory alkalosis
Platelet aggregation inhibition
Prolonged prothrombin time
Thrombocytopenia
Hepatotoxicity
Hearing loss
Renal damage
Bronchospasm
Pulmonary edema (salicylate-induced/noncardiogenic)
Reye syndrome
Warnings
Contraindications
Hypersensitivity to aspirin or NSAIDs
Hepatitis or severe hepatic/renal impairment
Do not use in children or adolescents with viral infections (eg, influenza, chickenpox) because of risk of Reye syndrome
Cautions
Many dosage forms, check label carefully!
Gastrointestinal bleeding; particular caution in patients w/ history of GI bleed, alcoholism, or bleeding disorders
Avoid w/ active peptic ulcer disease
Avoid in severe renal impairment (ie, CrCl <10 mL/min)
Avoid in severe hepatic impairment
Pregnancy and lactation
Pregnancy category: D; avoid during pregnancy, particularly in third trimester because of risk for premature closure of the ductus arteriosus
Lactation: excreted in breast milk; do not breast feed
Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs
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 Aspirin rectal
Mechanism of action
Inhibits prostaglandin synthesis by cyclooxygenase-1 and -2 via acetylation; inhibits formation of prostaglandin derivative, thromboxane A2 via acetylation of platelete cyclooxygenase, which in turn inhibits platelet aggregation
Pharmacokinetics
Absorption: 60%
Onset: 4-5 hr
Half-life: 4.7-9 hr
Protein Bound: 50-80%
Volume of Distribution: 150 mL/kg
Metabolism: Hydrolyzed by esterases in liver (mostly) & erythrocytes to salicylic acid
Metabolites: salicyluric acid, salicyl acyl glucuronide, salicyl phenolic glucuronide, gentisic acid
Excretion: (urine) 5.6-35.6% Hemodialysis: Yes
Pharmacogenomics
Aspirin associated hypersensitivity reactions include:
Aspirin-induced urticaria: associated with HLA-DRB1*1302-DQB1*0609 haplotype
Aspirin-intolerant asthma: associated with HLA-DPB1*0301
