Lofexidine Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Sep 27, 2024.

Applies to lofexidine: oral tablet.

Precautions

It is very important that your doctor check your progress while you are using this medicine to make sure this medicine is working properly and to check for unwanted effects.

This medicine may cause low blood pressure, slow heartbeat, or fainting. Contact your doctor right away if you have any changes to your heart rhythm. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

This medicine will add to the effects of alcohol and other central nervous system (CNS) depressants. CNS depressants are medicines that slow down the nervous system, which may cause drowsiness or make you less alert. Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicine, other prescription pain medicine or narcotics, medicine for anxiety or benzodiazepines, medicine for seizures or barbiturates, muscle relaxants, or anesthetics (numbing medicines), including some dental anesthetics. This effect may last for a few days after you stop using this medicine. Check with your doctor before taking any of the other medicines listed above while you are using lofexidine.

After a period of not using an opioid medicine, you may be more sensitive to its effects and at greater risk of overdosing. Talk to your doctor if you have concerns.

Do not suddenly stop using this medicine without first checking with your doctor. You may be directed to gradually reduce the amount you are using before stopping treatment completely to lessen the chance of unwanted side effects.

This medicine may make you dizzy, drowsy, or lightheaded. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve dizziness or lightheadedness.

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 lofexidine

Along with its needed effects, lofexidine 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 lofexidine:

Other side effects of lofexidine

Some side effects of lofexidine 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:

For healthcare professionals

Applies to lofexidine: oral tablet.

General adverse events

The more commonly reported adverse effects have included orthostatic hypotension, bradycardia, hypotension, dizziness, somnolence, sedation, and dry mouth.^[Ref]

Cardiovascular

• Very common (10% or more): Orthostatic hypotension (up to 42%); bradycardia (up to 32%); hypotension (30%), hypertension with abrupt discontinuation
• Uncommon (0.1% to 1%): Syncope
• Postmarketing reports: QT prolongation

Adverse reactions are reported at mean average daily doses up to 2.88 mg/day. With a mean dose of 2.16 mg/day, insomnia, orthostatic hypotension, bradycardia, and hypotension, were reported at 51%, 29%, 24%, and 30%, respectively. Syncope was reported in 0.9% of patients receiving 2.16 mg/day (1.4% for patients receiving 2.88 mg/day and 0% for placebo).

Blood pressure (BP) elevations of 140 mmHg (systolic) or higher, and above the subject's pretreatment BP, occurred in 39.7% (n= 23/58) of patients following discontinuation of a 5-day course of 2.88 mg/day. BP peaked on the second day after discontinuation.

Since market introduction (1992 in UK), there has been 1 case of QT prolongation, bradycardia, torsades de pointes, and cardiac arrest with successful resuscitation; there have been 3 reports of clinically significant QT prolongation in patients concomitantly receiving methadone.

Cardiac electrophysiology studies with single doses of 1.44 to 1.8 mg produced maximum mean change from baseline QTcF of 14.4 and 13.6 milliseconds, respectively in healthy normal volunteers. In a phase 3 study in opioid-dependent subjects, a maximal mean prolongation of the QTcF interval of 7.3 and 9.3 milliseconds occurred at doses of 2.16 and 2.88 mg/day respectively. In patients with renal or hepatic impairment, QT prolongation was reported; it was more pronounced in subjects with severe renal or hepatic impairment.

Nervous system

• Very common (10% or more): Dizziness (up to 23%), somnolence (up to 13%), sedation (up to 13%)

Gastrointestinal

• Very common (10% or more): Dry mouth (up to 11%)

Other

• Uncommon (0.1% to 1%): Tinnitus

Psychiatric

• Very common (10% or more): Insomnia (up to 55%)
• Frequency not reported: Withdrawal symptoms

Insomnia was reported in 51% of patients receiving a mean average daily dose of 2.16 mg/day and 55% of those receiving 2.88 mg/day; however, it was also reported by 48% of those receiving placebo.

For patients stopping this drug, a higher incidence of diarrhea, insomnia, anxiety, chills, hyperhidrosis, and extremity pain occurred in drug-treated patients compared to those taking placebo.

See also:

Frequently asked questions

• Is Lucemyra (lofexidine) a controlled drug?
• How long does lofexidine typically take to work?
• How do you get Lucemyra (lofexidine)?

Further information

Lofexidine 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.

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