Synalgos-DC Side Effects

Generic name: aspirin / caffeine / dihydrocodeine

Medically reviewed by Drugs.com. Last updated on Dec 11, 2024.

Note: This document provides detailed information about Synalgos-DC Side Effects associated with aspirin / caffeine / dihydrocodeine. Some dosage forms listed on this page may not apply specifically to the brand name Synalgos-DC.

Applies to aspirin / caffeine / dihydrocodeine: oral capsule.

Important warnings This medicine can cause some serious health issues

Oral route (capsule)

Respiratory depression and death have been reported in children following tonsillectomy or adenoidectomy.

These children had evidence of being ultra-rapid metabolizers due to a CYP2D6 polymorphism.

Common side effects of Synalgos-DC

Some side effects of aspirin / caffeine / dihydrocodeine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• difficulty having a bowel movement (stool)
• dizziness
• drowsiness
• itching skin
• lightheadedness
• nausea
• relaxed and calm feeling
• sleepiness
• vomiting

Serious side effects of Synalgos-DC

Along with its needed effects, aspirin/caffeine/dihydrocodeine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking aspirin/caffeine/dihydrocodeine:

Incidence not known

• abdominal pain, cramping, or tenderness
• bleeding gums
• blood in the urine or stools
• bloody, black, or tarry stools
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• constipation
• convulsions
• coughing or vomiting blood
• dark-colored urine
• heartburn
• hives or itching
• increased menstrual flow or vaginal bleeding
• indigestion
• large, flat, blue or purplish patches in the skin
• nausea or vomiting
• nosebleeds
• pains in the stomach, side, or abdomen, possibly radiating to the back
• pinpoint red or purple spots on the skin
• prolonged bleeding from cuts
• red or black, tarry stools or dark urine
• unusual bleeding or bruising
• unusual tiredness or weakness
• vomiting of material that looks like coffee grounds, severe and continuing

For healthcare professionals

Applies to aspirin / caffeine / dihydrocodeine: oral capsule.

General adverse events

The most frequently expected adverse reactions based on the individual components include lightheadedness, dizziness, drowsiness, sedation, nausea, vomiting, constipation, pruritus and skin reactions.^[Ref]

Gastrointestinal

Dihydrocodeine:

• Frequency not reported: Nausea, vomiting, constipation, abdominal pain, diarrhea, dry mouth, indigestion, spasm of biliary tract

Caffeine:

• Frequency not reported: Diarrhea, nausea, stomach pain, vomiting^[Ref]

Hypersensitivity

Dihydrocodeine:

• Frequency not reported: Anaphylactoid reactions, hypersensitivity reactions^[Ref]

Respiratory

Dihydrocodeine:

• Frequency not reported: Respiratory depression, cough suppression^[Ref]

Psychiatric

Dihydrocodeine:

• Frequency not reported: Confusion, physical and psychological dependence, hallucinations vivid dreams

Caffeine:

• Frequency not reported: Anxiety, anxiety neurosis, excitement, insomnia, irritability, restlessness, tenseness^[Ref]

Dermatologic

Dihydrocodeine:

• Frequency not reported: Sweating, pruritus, skin reactions

Caffeine:

• Frequency not reported: Urticaria^[Ref]

Cardiovascular

Dihydrocodeine:

• Frequency not reported: Orthostatic hypotension

Caffeine:

• Frequency not reported: Extrasystoles, palpitations, tachycardia^[Ref]

Endocrine

Opioids:

• Frequency not reported: Adrenal insufficiency, androgen deficiency^[Ref]

Chronic opioid use may influence the hypothalamic-pituitary-gonadal axis and lead to androgen deficiency; however, the causal role of opioids is unknown due to the lack of studies into the many medical, physical, lifestyle, and psychological stressors that influence gonadal hormone levels.^[Ref]

Genitourinary

Dihydrocodeine:

• Frequency not reported: Urinary retention^[Ref]

Metabolic

Dihydrocodeine:

• Frequency not reported: Anorexia^[Ref]

Nervous system

Dihydrocodeine:

• Rare (less than 0.1%): Narcosis
• Frequency not reported: Lightheadedness, dizziness, drowsiness, sedation, headache

Caffeine:

• Frequency not reported: Headaches, lightheadedness, tremor

Opioids:

• Frequency not reported: Serotonin syndrome^[Ref]

Ocular

Dihydrocodeine:

• Frequency not reported: Miosis

Caffeine:

• Frequency not reported: Scintillating scotoma^[Ref]

Other

Dihydrocodeine:

• Frequency not reported: Fatigue

Caffeine:

• Frequency not reported: Tinnitus^[Ref]

Renal

Dihydrocodeine:

• Rare (less than 0.1%): Acute renal failure
• Frequency not reported: Granulomatous interstitial nephritis

Caffeine:

• Frequency not reported: Diuresis^[Ref]

Further information

Synalgos-DC side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer