Dosing and uses of Synalgos-DC (dihydrocodeine/aspirin/caffeine)
Adult dosage forms and strengths
dihydrocodeine/aspirin/caffeine
capsule: Schedule V
- 16mg/356.4mg/30mg
Moderate-to-Severe Pain
2 capsules PO q4hr prn
Pediatric dosage forms and strengths
Safety and efficacy not established
Synalgos-DC (dihydrocodeine/aspirin/caffeine) adverse (side) effects
Frequency not defined
Dihydrocodeine
- Light-headedness
- Dizziness
- Drowsiness
- Headache
- Fatigue
- Sedation
- Confusion
Aspirin
- Stomach pain
- Heartburn
- Nausea
- Vomiting
- Dyspepsia
- Tinnitus (high or chronic dose)
- Rash
Caffeine
- Insomnia
- Restlessness
- Nervousness
- Tremor
- Tinnitus
- Irritability
- Nausea
Warnings
Black box warnings
Postoperative pain in children
- Deaths have occurred in children with obstructive sleep apnea who receive codeine for postoperative pain following tonsillectomy and/or adenoidectomy
- Codeine is converted to morphine by the liver; these children had evidence of being ultra-rapid metabolizers (via CYP2D6) of codeine, which is an inherited (genetic) ability that causes codeine to be converted rapidly into life-threatening or fatal amounts of morphine (see Pharmacology)
Contraindications
Hypersensitivity
Any situation where opioids are contraindicated including significant respiratory depression (in unmonitored settings or in the absence of resuscitation equipment), acute or severe bronchial asthma or hypercapnia, and paralytic ileus
Postoperative use in children following tonsillectomy and/or adenoidectomy (see Black box warnings)
Cautions
May impair mental/physical abilities required for hazardous tasks (eg, driving, operating machinery)
May cause respiratory depression
Caution is used with head injury or increased ICp
May cause hypotension
Dihydrocodeine can produce drug dependence
Caution in elderly or debilitated patients, or in patients with following conditions: adrenocortical insufficiency (Addison disease), asthma, central nervous system depression or coma, chronic obstructive pulmonary disease, decreased respiratory reserve (including emphysema, severe obesity, cor pulmonale, or kyphoscoliosis), delirium tremens, head injury, hypotension, increased intracranial pressure, myxedema or hypothyroidism, prostatic hypertrophy or urethral stricture, and toxic psychosis
Use opioids with caution with MAOIs
Caution with a history of drug abuse
Gastrointestinal bleeding; particular caution in patients with history of GI bleed, alcoholism, or bleeding disorders
Avoid with active peptic ulcer disease
Avoid in severe renal impairment (ie, CrCl <10 mL/min)
Avoid in severe hepatic impairment
Caffeine may produce CNS/CV stimulation and GI irritation
Pregnancy and lactation
Pregnancy category: D; avoid aspirin during pregnancy, particularly in third trimester because of risk for premature closure of the ductus arteriosus
Lactation: Distributed in breast milk in small amounts, caution advised
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 Synalgos-DC (dihydrocodeine/aspirin/caffeine)
Mechanism of action
Dihydrocodeine: Semisynthetic opioid agonist analgesic related to codeine
Aspirin: Acts on hypothalamus to produce antipyresis; anti-inflammatory properties attributed to prostaglandin synthetase inhibition resulting in decreased formation of thromboxane A2
Caffeine: Vasoconstrictive properties may be helpful when treating vascular headaches
Pharmacogenomics
10% of codeine is metabolized to morphine by CYP2D6; the active morphine metabolite has a higher affinity for opioid receptors
CYP2D6 poor metabolizers may not achieve adequate analgesia
Ultra-rapid metabolizers (up to 7% of Caucasians and up to 30% of Asian and African populations) may have increased toxicity due to rapid conversion
