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Tenex Side Effects

Generic Name: guanfacine

Note: This page contains side effects data for the generic drug guanfacine. It is possible that some of the dosage forms included below may not apply to the brand name Tenex.

In Summary

Common side effects of Tenex include: weakness, drowsiness, constipation, dizziness, fatigue, and xerostomia. Other side effects include: impotence. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to guanfacine: oral tablet, oral tablet extended release

As well as its needed effects, guanfacine (the active ingredient contained in Tenex) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking guanfacine, check with your doctor immediately:

More common:
  • Blurred vision
  • confusion
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • sweating
  • unusual tiredness or weakness
Less common:
  • Chest pain or discomfort
  • cough
  • difficulty with breathing
  • fast, slow, or irregular heartbeat
  • increased need to urinate
  • lightheadedness, dizziness, or fainting
  • mental depression
  • noisy breathing
  • passing urine more often
  • pounding heartbeat
  • tightness in the chest

If any of the following symptoms of overdose occur while taking guanfacine, get emergency help immediately:

Symptoms of overdose:
  • Dizziness (extreme) or faintness
  • unusual tiredness or weakness (severe)

Minor Side Effects

Some guanfacine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Constipation
  • dizziness
  • drowsiness
  • dryness of the mouth
  • headache
  • irritability
  • nausea
  • sleepiness or unusual drowsiness
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
  • upper abdominal or stomach pain
  • vomiting
  • weight gain
Less common:
  • Acid or sour stomach
  • belching
  • decreased appetite
  • decreased sexual ability
  • dry, itching, or burning eyes
  • heartburn
  • indigestion
  • lack or loss of strength
  • paleness of the skin
  • stomach discomfort, upset, or pain
  • trouble with sleeping

Side Effects: Post Treatment

After you stop taking this drug, it is possible that you may still experience side effects that need medical attention. If you notice any of the following side effects check with your doctor immediately:

  • Anxiety or tenseness
  • increased salivation
  • nervousness or restlessness
  • shaking or trembling of the hands and fingers
  • stomach cramps
  • sweating

For Healthcare Professionals

Applies to guanfacine: oral tablet, oral tablet extended release

General

The most common adverse reactions were dry mouth, somnolence, headache, fatigue, dizziness, abdominal pain, constipation, appetite decreased, and sedation.[Ref]

Gastrointestinal

Very common (10% or more): Dry mouth (up to 54%), abdominal pain (up to 15%), constipation (up to 15%)
Common (1% to 10%): Vomiting, diarrhea, nausea, abdominal/stomach discomfort
Uncommon (0.1% to 1%): Dyspepsia[Ref]

Nervous system

Very common (10% or more): Somnolence (up to 40.6%), headache (up to 28%), dizziness (up to 16%), sedation (10.2%)
Common (1% to 10%): Lethargy, convulsion, dizziness postural, syncope
Rare (less than 0.1%): Hypersomnia
Postmarketing reports: Tremor, paresthesias, vertigo, taste alteration[Ref]

Other

Very common (10% or more): Fatigue (up to 22%)
Common (1% to 10%): Asthenia
Uncommon (0.1% to 1%): Chest pain
Rare (less than 0.1%): Malaise[Ref]

Metabolic

Very common (10% or more): Appetite decreased (up to 15%)
Common (1% to 10%): Weight increased
Frequency not reported: Body mass index increased
Postmarketing reports: Edema

Psychiatric

Common (1% to 10%): Insomnia, depression, anxiety, affect lability, middle insomnia, nightmare, irritability
Uncommon (0.1% to 1%): Agitation, hallucination
Postmarketing reports: Confusion[Ref]

Cardiovascular

Common (1% to 10%): Hypotension, bradycardia, orthostatic hypotension, tachycardia
Uncommon (0.1% to 1%): Pallor, atrioventricular block first degree, sinus arrhythmia, blood pressure increased, heart rate decreased
Rare (less than 0.1%): Hypertension
Frequency not reported: QTc prolongation
Postmarketing reports: Palpitations

Genitourinary

Common (1% to 10%): Impotence, enuresis
Uncommon (0.1% to 1%): Pollakiuria
Frequency not reported: Urinary frequency increased[Ref]

Dermatologic

Common (1% to 10%): Rash, pruritus
Postmarketing reports: Alopecia, dermatitis, exfoliative dermatitis

Respiratory

Uncommon (0.1% to 1%): Asthma
Postmarketing reports: Dyspnea

Hepatic

Uncommon (0.1% to 1%): ALT increased

Immunologic

Uncommon (0.1% to 1%): Hypersensitivity

Musculoskeletal

Postmarketing reports: Arthralgia, leg cramps, leg pain, myalgia

Ocular

Postmarketing reports: Blurred vision

References

1. "Product Information. Intuniv (guanfacine)." Shire US Inc, Florence, KY.

2. "Product Information. Tenex (guanfacine)." Wyeth-Ayerst Laboratories, Philadelphia, PA.

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

It is possible that some side effects of Tenex may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.

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