K-Flex (Generic)

Orphenadrine is used to treat muscle spasms/pain. It is usually used along with rest, physical therapy, and other treatment.

This medication is given by injection into a vein or muscle by a health care professional. It is given as directed by your doctor, usually twice a day (every 12 hours). If this medication is injected into a vein, it should be given over 5 minutes while you are lying down. Continue to lie down for 5 to 10 minutes after the injection to reduce dizziness and lightheadedness.

To continue to control your symptoms, your doctor may switch you to a form of orphenadrine that is taken by mouth.

Tell your doctor if your condition does not improve or if it worsens.

Dry mouth, dizziness, drowsiness, lightheadedness, blurred vision, nausea, vomiting, and constipation may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as confusion, anxiety, hallucinations), shaking (tremor), fast/pounding heartbeat, fainting, difficulty urinating, eye pain.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using orphenadrine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as sulfites), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: high pressure in the eye (glaucoma), stomach/intestinal/esophagus problems (such as ulcers, blockage), difficulty urinating (such as due to enlarged prostate), a certain type of muscle/nerve disease (myasthenia gravis), heart problems (such as fast/irregular heartbeat, heart failure).

This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially confusion, drowsiness, constipation, or trouble urinating. Confusion and drowsiness can increase the risk of falling.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Not applicable. This medication is given in a hospital or clinic and will not be stored at home.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), other muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: unusual excitement, fast/irregular heartbeat, seizures.

Not applicable.

Keep all medical and laboratory appointments.

If you are using this medication for a long time, laboratory and/or medical tests may be performed periodically to check for side effects. Consult your doctor for more details.