warnings and cautions
5 WARNINGS AND PRECAUTIONS • Risk of Hypotension, Bradycardia, and Syncope: May cause a decrease in blood pressure, a decrease in pulse, and syncope. Monitor vital signs before dosing and advise patients on how to minimize the risk of these cardiovascular effects and manage symptoms, should they occur. Monitor symptoms related to bradycardia and orthostasis. When using in outpatients, ensure that patients are capable of self-monitoring signs and symptoms. Avoid use in patients with severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, or chronic renal failure, as well as in patients with marked bradycardia. ( 5.1 ) • Risk of QT Prolongation: lofexidine tablets prolongs the QT interval. Avoid use in patients with congenital long QT syndrome. Monitor ECG in patients with electrolyte abnormalities, congestive heart failure, bradyarrhythmias, hepatic or renal impairment, or in patients taking other medicinal products that lead to QT prolongation. ( 5.2 ) • Increased Risk of CNS Depression with Concomitant use of CNS Depressant Drugs: lofexidine tablets potentiates the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs. ( 5.3 ) • Increased Risk of Opioid Overdose after Opioid Discontinuation: Patients who complete opioid discontinuation are at an increased risk of fatal overdose should they resume opioid use. Use in conjunction with comprehensive management program for treatment of opioid use disorder and inform patients and caregivers of increased risk of overdose. ( 5.4 ) • Risk of Discontiuation Symptoms: Instruct patients not to discontinue therapy without consulting their healthcare provider. When discontinuing therapy, reduce dose gradually. ( 5.5 ) 5.1 Risk of Hypotension, Bradycardia and Syncope Lofexidine tablet can cause a decrease in blood pressure, a decrease in pulse, and syncope [see Adverse Reactions (6.1), Clinical Pharmacology (12.2) ] . Monitor vital signs before dosing. Monitor symptoms related to bradycardia and orthostasis. Patients being given lofexidine tablet in an outpatient setting should be capable of and instructed on self-monitoring for hypotension, orthostasis, bradycardia, and associated symptoms. If clinically significant or symptomatic hypotension and/or bradycardia occur, the next dose of lofexidine tablet should be reduced in amount, delayed, or skipped. Inform patients that lofexidine tablet may cause hypotension and that patients moving from a supine to an upright position may be at increased risk for hypotension and orthostatic effects. Instruct patients to stay hydrated, on how to recognize symptoms of low blood pressure, and how to reduce the risk of serious consequences should hypotension occur (e.g., sit or lie down, carefully rise from a sitting or lying position). Instruct outpatients to withhold lofexidine tablet doses when experiencing symptoms of hypotension or bradycardia and to contact their health care provider for guidance on how to adjust dosing. Avoid use lofexidine tablets in patients with severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, chronic renal failure, and in patients with marked bradycardia. Avoid use lofexidine tablets in combination with medications that decrease pulse or blood pressure to avoid the risk of excessive bradycardia and hypotension. 5.2 Risk of QT Prolongation Lofexidine tablet prolongs the QT interval. Avoid using lofexidine tablet in patients with congenital long QT syndrome. Monitor ECG in patients with congestive heart failure, bradyarrhythmias, hepatic impairment, renal impairment, or patients taking other medicinal products that lead to QT prolongation (e.g. methadone). In patients with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), correct these abnormalities first, and monitor ECG upon initiation of lofexidine tablet [see Dosing and Administration (2.1) Adverse Reactions (6.1), Special Populations (8.6)(8.7), Clinical Pharmacology (12.2) ]. 5.3 Increased Risk of Central Nervous System Depression with Concomitant use of CNS Depressant Drugs Lofexidine tablet potentiates the CNS depressive effects of benzodiazepines, and can also be expected to potentiate the CNS depressive effects of alcohol, barbiturates, and other sedating drugs. Advise patients to inform their healthcare provider of other medications they are taking, including alcohol. Advise patients using lofexidine tablet in an outpatient setting that, until they learn how they respond to lofexidine tablet, they should be careful or avoid doing activities such as driving or operating heavy machinery. 5.4 Increased Risk of Opioid Overdose after Opioid Discontinuation Lofexidine tablet is not a treatment for opioid use disorder. Patients who complete opioid discontinuation are likely to have a reduced tolerance to opioids and are at increased risk of fatal overdose should they resume opioid use. Use lofexidine tablet in patients with opioid use disorder only in conjunction with a comprehensive management program for the treatment of opioid use disorder and inform patients and caregivers of this increased risk of overdose. 5.5 Risk of Discontinuation Symptoms Stopping lofexidine tablet abruptly can cause a marked rise in blood pressure. Symptoms including diarrhea, insomnia, anxiety, chills, hyperhidrosis, and extremity pain have also been observed with lofexidine tablet discontinuation. Instruct patients not to discontinue therapy without consulting their healthcare provider. When discontinuing therapy with lofexidine tablet, gradually reduce the dose [see Dosing and Administration (2.1) ]. Symptoms related to discontinuation can be managed by administration of the previous lofexidine tablet dose and subsequent taper.