An open-label postmarketing study involving 21,718 patients was conducted to assess the safety of guanfacine (as the hydrochloride) 1 mg/day given at bedtime for 28 days. Guanfacine was administered with or without other antihypertensive agents. Adverse events reported in the postmarketing study at an incidence greater than 1% included dry mouth, dizziness, somnolence, fatigue, headache, and nausea. The most commonly reported adverse events in this study were the same as those observed in controlled clinical trials.
Less frequent, possibly guanfacine-related events observed in the postmarketing study and/or reported spontaneously include:
BODY AS A WHOLE: asthenia, chest pain, edema, malaise, tremor
CARDIOVASCULAR: bradycardia, palpitations, syncope, tachycardia
CENTRAL NERVOUS SYSTEM: paresthesias, vertigo
EYE DISORDERS: blurred vision
GASTROINTESTINAL SYSTEM: abdominal pain, constipation, diarrhea, dyspepsia
LIVER AND BILIARY SYSTEM: abnormal liver function tests
MUSCULOSKELETAL SYSTEM: arthralgia, leg cramps, leg pain, myalgia
PSYCHIATRIC: agitation, anxiety, confusion, depression, insomnia,
REPRODUCTIVE SYSTEM, MALE: impotence
RESPIRATORY SYSTEM: dyspnea
SKIN AND APPENDAGES: alopecia, dermatitis, exfoliative dermatitis, pruritus,
SPECIAL SENSES: alterations in taste
URINARY SYSTEM: nocturia, urinary frequency
Rare, serious disorders with no definitive cause and effect relationship to guanfacine have been reported spontaneously and/or in the postmarketing study. These events include acute renal failure, cardiac fibrillation, cerebrovascular accident, congestive heart failure, heart block, and myocardial infarction.
No reported abuse or dependence has been associated with the administration of guanfacine.
Drowsiness, lethargy, bradycardia, and hypotension have been observed following overdose with guanfacine.
A 25-year-old female intentionally ingested 60 mg. She presented with severe drowsiness and bradycardia of 45 beats/minute. Gastric lavage was performed and an infusion of isoproterenol (0.8 mg in 12 hours) was administered. She recovered quickly and without sequelae.
A 28-year-old female who ingested 30-40 mg developed only lethargy, was treated with activated charcoal and a cathartic, was monitored for 24 hours, and was discharged in good health.
A 2-year-old male weighing 12 kg, who ingested up to 4 mg of guanfacine, developed lethargy. Gastric lavage (followed by activated charcoal and sorbitol slurry via NG tube) removed some tablet fragments within 2 hours after ingestion, and vital signs were normal.
During 24-hour observation in ICU, systolic pressure was 58 and heart rate 70 at 16 hours post-ingestion. No intervention was required, and child was discharged fully recovered the next day.
Gastric lavage and supportive therapy as appropriate. Guanfacine is not dialyzable in clinically significant amounts (2.4%).
The recommended initial dose of guanfacine (as the hydrochloride) when given alone or in combination with another antihypertensive drug is 1 mg daily given at bedtime to minimize somnolence. If after 3 to 4 weeks of therapy, 1 mg does not give a satisfactory result, a dose of 2 mg may be given, although most of the effect of guanfacine is seen at 1 mg (see CLINICAL PHARMACOLOGY). Higher daily doses have been used, but adverse reactions increase significantly with doses above 3 mg/day.
The frequency of rebound hypertension is low, but it can occur. When rebound occurs, it does so after 2-4 days, which is delayed compared with clonidine hydrochloride. This is consistent with the longer half-life of guanfacine. In most cases, after abrupt withdrawal of guanfacine, blood pressure returns to pretreatment levels slowly (within 2-4 days) without ill effects.
Guanfacine Tablets USP, 1 mg are available as white, round, flat-faced beveled-edge tablets, debossed “ Є 48” on one side and plain on the other side. These are supplied:
NDC 24658-730-01 Bottles of 100 Tablets
Guanfacine Tablets USP, 2 mg are available as yellow, round, flat-faced beveled-edge tablets, debossed “ Є 49” on one side and plain on the other side. These are supplied:
NDC 24658-731-01 Bottles of 100 Tablets
Store at 20°-25°C (68°-77°F). [See USP controlled room temperature.]
Dispense in a tight, light-resistant container.
PuraCap Laboratories, LLC
DBA Blu Pharmaceuticals
Franklin, KY 42134 USA
Manufactured in USA
Issued August 2016
Guanfacine Tablets USP, 1 mg
Guanfacine Tablets USP, 2 mg
| GUANFACINE |
| GUANFACINE |
|Labeler — PuraCap Laboratories LLC dba Blu Pharmaceuticals (080210964)|
|Registrant — Epic Pharma, LLC (827915443)|
|Epic Pharma, LLC||827915443||manufacture (24658-730), manufacture (24658-731)|
Revised: 01/2019 PuraCap Laboratories LLC dba Blu Pharmaceuticals
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