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guanfacine (Rx)Brand and Other Names:Intuniv, Tenex

 
 
 

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet (Tenex)

  • 1mg
  • 2mg
more...

Hypertension

Tenex: 1 mg PO qHS; may increase to 2 mg after 3-4 weeks

Usual range 0.5-2 mg/day

Do not exceed 3 mg qDay due to increased risk of adverse effects

Heroin Withdrawal (Off-label)

0.03-1.75 mg/day PO for 5-15 days

Migraine Prophylaxis (Off-label)

Initial: 1 mg/day; do not exceed 3 mg/day

Fragile X Syndrome (Orphan)

Orphan sponsor

  • Watson Laboratories, Inc; 311 Bonnie Circle, PO Box 1900; Corona, CA 91718-1900

Dosage Modifications

Strong or moderate CYP3A4 inhibitors

  • Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations
  • FDA-labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the reommended dose; specific recommendations for immediate-release (IR) guanfacine are not available
  • Starting therapy while currently taking CYP3A4 inhibitor: Decrease dose to half the recommended level
  • Continuing therapy while adding CYP3A4 inhibitor: Decrease dose to half the recommended level
  • Continuing therapy while stopping CYP3A4 inhibitor: Increase dose to recommended level

Strong or moderate CYP3A4 inducers

  • CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life
  • If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response
  • For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered
  • Starting therapy while currently taking CYP3A4 inducer: Increase dose up to double the recommended level
  • Continuing therapy while adding CYP3A4 inducer: Increase dose up to double the recommended level over 1-2 weeks
  • Continuing therapy while stopping CYP3A4 inducer: Increase dose to recommended level

Dosage Forms & Strengths

tablet (Tenex)

  • 1mg
  • 2mg

tablet, extended-release (Intuniv)

  • 1mg
  • 2mg
  • 3mg
  • 4mg
more...

Hypertension

<12 years

  • Safety and efficacy not established

≥12 years

  • Tenex: 1 mg PO qHS; may increase to 2-3 mg after 3-4 weeks
  • Usual range: 0.5-2 mg/day

Attention Deficit Hyperactivity Disorder

Intuniv: Monotherapy for ADHD or adjunct to stimulants

<6 years: Safety and efficacy not established

6-18 years

  • Intuniv: 1 mg/day PO initially; may adjust dose using increasing increments (not exceeding 1 mg/wk)
  • Take once daily, either in the morning or evening, at approximately the same time each day
  • To balance the exposure-related potential benefits and risks, the recommended target dose range depending on clinical response and tolerability is0.05-0.12 mg/kg/day PO initially 
  • Aged 6-12 years: Doses >4 mg/day not evaluated
  • Aged 13-17 years: Doses >7 mg/day not evaluated
  • Adjunctive trials with psychostimulants: Doses >4 mg/day not evaluated

Target dose range by weight

  • 25-33.9 kg: 2-3 mg/day
  • 34-41.4 kg: 2-4 mg/day
  • 41.5-49.4 kg: 3-5 mg/day
  • 49.5-58.4 kg: 3-6 mg/day
  • 58.5-91 kg: 4-7 mg/day
  • >91 kg: 5-7 mg/day

Dosage Modifications

Strong or moderate CYP3A4 inhibitors

  • Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations
  • FDA-labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the reommended dose; specific recommendations for immediate-release (IR) guanfacine are not available
  • Starting therapy while currently taking CYP3A4 inhibitor: Decrease dose to half the recommended level
  • Continuing therapy while adding CYP3A4 inhibitor: Decrease dose to half the recommended level
  • Continuing therapy while stopping CYP3A4 inhibitor: Increase dose to recommended level

Strong or moderate CYP3A4 inducers

  • CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life
  • If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response
  • For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered
  • Starting therapy while currently taking CYP3A4 inducer: Increase dose up to double the recommended level
  • Continuing therapy while adding CYP3A4 inducer: Increase dose up to double the recommended level over 1-2 weeks
  • Continuing therapy while stopping CYP3A4 inducer: Increase dose to recommended level

Dosing Considerations

Immediate-release and extended-release formulations are not interchangeable due to differences in bioavailability

Tourette Syndrome (Orphan)

Orphan designation for combination of guanfacine and amphetamine to treatment Tourette syndrome

Sponsor

  • Genco Sciences, LLC; 1011 Greenwood Avenue; Willmette, Illinois 60091
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Interactions

Interaction Checker

guanfacine and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            Sort by :  
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            Adverse Effects

            >10%

            Xerostomia (10-60%)

            Somnolence (5-39%)

            Headache (0.2-26%)

            Dizziness (2-15%)

            Constipation (2-16%)

            Fatigue (2-15%)

            Abdominal pain (11%)

            1-10%

            Hypotension (7%)

            Asthenia (2-7%)

            Impotence (0-7%)

            Lethargy (6%)

            Dizziness (6%)

            Irritability (6%)

            Nausea (3-6%)

            Decreased appetite (5%)

            Weakness (1-5%)

            Insomnia (3-4%)

            Bradycardia (3%)

            Palpitations (3%)

            Confusion (3%)

            Depression (3%)

            Dyspnea (3%)

            Alopecia (3%)

            Dermatitis (3%)

            Diaphoresis (3%)

            Pruritus (3%)

            Dyspepsia (3%)

            Dysphagia (3%)

            Hypokinesia (3%)

            Leg cramps (3%)

            Frequency Not Defined

            Orthostatic hypotension

            Exfoliation

            Rash

            Arthralgia

            Myalgia

            Postmarketing Reports

            Cardiovascular: Bradycardia, palpitations, syncope, tachycardia

            CNS: Paresthesias, vertigo

            GI: Abdominal pain, constipation, diarrhea, dyspepsia

            Liver/biliary: Abnormal LFTs

            Musculoskeletal: Arthralgia, leg cramps, leg pain, myalgia

            Psychiatric: Agitation, anxiety, confusion, depression, hallucinations, insomnia, nervousness

            Reproductive: Impotence

            Respiratory: Dyspnea

            Skin: Alopecia, dermatitis, exfoliative dermatitis, pruritus, rash

            Sensory: Blurred vision, alterations in taste

            Urinary: Nocturia, urinary frequency

            Other: Asthenia, chest pain, edema, malaise, tremor

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            Warnings

            Contraindications

            Hypersensitivity

            Cautions

            Avoid abrupt withdrawal (can result in anxiety, nervousness, and rebound hypertension)

            May cause hypotension, orthostasis, bradycardia, and syncope, use with caution in history of cerebrovascular disease, recent MI, severe coronary insufficiency, or syncope

            Chronic renal/hepatic failure

            May cause sedation, especially at start; avoid operating heavy machinery

            Skin rash with exfoliation reported

            Avoid concomitant use with other CNS depressants (eg, alcohol) as they may potentiate CNS effects

            Risk of cardiovascular effects may increase when administered concurrently with antihypertensive medications or drugs that affect heart rate

            ADHD

            • Hypotension is dose-limiting
            • Do not substitute extended-release tablet for immediate-release guanfacine on a mg/mg basis, because of differing pharmacokinetic profiles
            • May cause dose-dependent hypotension, bradycardia, and syncope
            • Hallucinations reported in children with ADHD treated with guanfacine

            Geriatric patients

            • May cause adverse CNS effects
            • May cause bradycardia and orthostatic hypotension
            • Not recommended as routine treatment for hypertension (Beers criteria)
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            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Unknown if excreted into breast milk; use caution

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

            more...
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            Pharmacology

            Mechanism of Action

            Selective alpha2-adrenergic receptor agonist causing decreased sympathetic outflow and subsequent decrease in vasomotor tone and heart rate; may preferentially bind postsynaptic alpha2A adrenoreceptors in the prefrontal cortex, which may improve delay-related firing of prefrontal cortex neurons (as a result, behavioral inhibition may be affected); mechanism of action in ADHD is not known

            Absorption

            Bioavailability: Immediate-release (80-100%); extended-release (58%)

            Onset: Initial effect (2 hr); maximum effect (6 hr)

            Duration: 24 hr

            Peak plasma time: Immediate release (1-4 hr); extended release (4-8 hr)

            Distribution

            Protein bound: 70%

            Vd: 6.3 L/kg

            Metabolism

            Via CYP3A4 (hepatic)

            Metabolites: Glucuronide and sulfate of 3-hydroxy guanfacine, oxidized mercapturic acid derivatives (inactive)

            Elimination

            Half-life: Immediate release (17 hr); extended release (16 hr)

            Dialyzable: HD (No)

            Excretion: Urine 80% (unchanged)

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            Administration

            ADHD (extended-release tablet [Intuniv])

            Do not administer with high-fat meals due to potential for increased serum levels

            Swallow tablets whole; do not crush, chew, or break tablets because this will increase the rate of guanfacine release

            If extended-release dose missed, repeat dosage titration based on patient tolerability

            Discontinuing: Taper by decrements not exceeding 1 mg q3-7Days to avoid rebound hypertension

            Switching from immediate-release tablet

            Discontinue immediate-release tablet and titrate with extended-release tablet as described above

            Do not substitute for immediate-release guanfacine tablets on a mg-per-mg basis, because of differing pharmacokinetic profiles

            Intuniv has significantly reduced peak plasma levels (60% lower), bioavailability (43% lower), and a delayed time to peak levels (3 hr later) compared to those of the same dose of immediate-release guanfacine

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            Images

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            Formulary

            FormularyPatient Discounts

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

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            • Compare formulary status to other drugs in the same class.
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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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