Antiflex Side Effects
Generic name: orphenadrine
Medically reviewed by Drugs.com. Last updated on Aug 2, 2024.
Note: This document provides detailed information about Antiflex Side Effects associated with orphenadrine. Some dosage forms listed on this page may not apply specifically to the brand name Antiflex.
Applies to orphenadrine: oral tablet extended release.
Other dosage forms:
Precautions
It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects .
Orphenadrine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Check with your doctor right away if you have a rash; itching; swelling of the face, tongue, and throat; trouble with breathing; or chest pain after using this medicine .
This medicine may cause some people to become dizzy, lightheaded, faint, or less alert than they are normally. It may also cause muscle weakness in some people. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert and able to see well.
This medicine may add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; other muscle relaxants; or anesthetics, including some dental anesthetics. Do not drink alcoholic beverages, and check with your doctor before taking any of the medicines listed above, while you are using this medicine.
Orphenadrine may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if dry mouth continues for more than 2 weeks, check with your dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements. .
Serious side effects of Antiflex
Along with its needed effects, orphenadrine (the active ingredient contained in Antiflex) 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 orphenadrine:
Rare side effects
- chest pain
- chills
- cough
- fever
- hallucinations (seeing, hearing, or feeling things that are not there)
- headache
- shortness of breath, troubled breathing, tightness in chest, and/or wheezing
- skin rash, hives, itching, or redness
- sores, ulcers, or white spots on lips or in mouth
- swollen and/or painful glands
- unusual bruising or bleeding
- unusual tiredness or weakness
Incidence not known
- abdominal or stomach pain
- diarrhea
- fainting
- fast, pounding irregular heartbeat or pulse
- glaucoma
- joint or muscle pain
- nausea
- numbness or tingling of face, hands, or feet
- redness and soreness of eyes
- swelling of feet or lower legs
- vomiting
Get emergency help immediately if any of the following symptoms of overdose occur while taking orphenadrine:
Symptoms of Overdose
- blurred vision
- confusion, delirium, or hallucinations
- constipation
- difficult urination
- drowsiness
- dry eyes, mouth, nose, or throat
- eye pain
- flushing or redness of face
- troubled breathing
Other side effects of Antiflex
Some side effects of orphenadrine 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:
Less common or rare side effects
- dizziness or lightheadedness
- excitement, irritability, nervousness, or restlessness
- headache
- muscle weakness
- unusually large pupils of eyes
Incidence not known
- anxiety
- deep or fast breathing with dizziness
- itching skin
- mental confusion
- numbness of feet, hands and around mouth
- trembling or shaking of hands or feet shakiness in legs, arms, hands, or feet
For healthcare professionals
Applies to orphenadrine: compounding powder, injectable solution, oral tablet extended release.
General adverse events
The more commonly reported adverse reactions are due to the anticholinergic effects of this drug; dry mouth is usually the first adverse effect to appear.
Hypersensitivity
- Rare (less than 0.1%): Anaphylaxis (with IM injection)
- Frequency not reported: Hypersensitivity reactions
Nervous system
- Frequency not reported: Headache, light-headedness, dizziness, drowsiness, syncope, tremor, sedation, convulsions, coordination difficulties[Ref]
Psychiatric
- Rare (less than 0.1%): Memory disturbances
- Frequency not reported: Hallucinations, agitation, euphoria, restlessness, mental confusion (especially elderly)[Ref]
Ocular
- Frequency not reported: Blurred vision, dilatation of pupils, increased ocular tension, accommodation disorders[Ref]
Cardiovascular
- Frequency not reported: Tachycardia, palpitations[Ref]
Gastrointestinal
- Frequency not reported: Dry mouth, nausea, vomiting, constipation, gastric irritation[Ref]
Genitourinary
- Frequency not reported: Urinary hesitancy, urinary retention[Ref]
Musculoskeletal
- Frequency not reported: Weakness[Ref]
Dermatologic
Hematologic
- Rare (less than 0.1%): Aplastic anemia[Ref]
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References
1. (2001) "Product Information. Norflex (orphenadrine)." 3M Pharmaceuticals
More about Antiflex (orphenadrine)
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- During pregnancy
- Drug class: skeletal muscle relaxants
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Patient resources
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Professional resources
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Further information
Antiflex 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.