Tramadol

12.1 Mechanism of Action Tramadol hydrochloride extended-release tablets contain tramadol, an opioid agonist and an inhibitor of reuptake of norepinephrine and serotonin. Although the mode of action of tramadol is not completely understood, the analgesic effect of tramadol is believed to be due to both binding to μ-opioid receptors and weak inhibition of reuptake of norepinephrine and serotonin. Opioid activity of tramadol is due to both low affinity binding of the parent compound and higher affinity binding of the O-desmethyl metabolite M1 to μ-opioid receptors. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in μ-opioid binding. Tramadol-induced analgesia is only partially antagonized by the opioid antagonist naloxone in several animal tests. The relative contribution of both tramadol and M1 to human analgesia is dependent upon the plasma concentrations of each compound. Tramadol has been shown to inhibit reuptake of norepinephrine and serotonin in vitro , as have some other opioid analgesics. These mechanisms may contribute independently to the overall analgesic profile of tramadol. Apart from analgesia, tramadol administration may produce a constellation of symptoms (including dizziness, somnolence, nausea, constipation, sweating and pruritus) similar to that of other opioids. In contrast to morphine, tramadol has not been shown to cause histamine release. At therapeutic doses, tramadol has no effect on heart rate, left-ventricular function, or cardiac index. Orthostatic hypotension has been observed.

1 INDICATIONS AND USAGE Tramadol hydrochloride extended-release tablets are indicated for the management of severe and persistent pain that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. Limitations of Use • Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosages or duration, and persist over the course of therapy, [see Warnings and Precautions (5.1)], reserve opioid analgesics, including tramadol hydrochloride extended-release tablets, for use in patients for whom alternative treatment options are ineffective, not tolerated or would be otherwise inadequate to provide sufficient management of pain. • Tramadol hydrochloride extended-release tablets are not indicated as an as-needed (prn) analgesic. Tramadol hydrochloride extended-release tablets are an opioid agonist indicated for the management of severe and persistent pain that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. (1) Limitations of Use Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosages or duration and persist over the course of therapy, reserve opioids analgesics, including tramadol hydrochloride extended-release tablets, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. (1) Tramadol hydrochloride extended-release tablets are not indicated as an as-needed (prn) analgesic. (1)

2 DOSAGE AND ADMINISTRATION Tramadol hydrochloride extended-release tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. (2.1) Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of tramadol hydrochloride extended-release tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. (2.1, 5) Initiate the dosing regimen for each patient individually, taking into account the patient’s underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse. (2.1, 5.1) Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments. (2.1, 5.2) Discuss opioid overdose reversal agents and options for acquiring them with the patient and/or caregiver, both when initiating and renewing treatment with tramadol hydrochloride extended-release tablets, especially if the patient has additional risk factors for overdose, or close contacts at risk for exposure and overdose. (2.2, 5.1, 5.2, 5.3) Tramadol hydrochloride extended-release tablets should be taken once daily, at approximately the same time every day. (2.3) For patients currently on tramadol IR, calculate total 24-hr IR dose, and initiate tramadol hydrochloride extended-release tablets at a dose rounded down to next lower 100 mg increment; then adjust dose according to need and tolerance. See full prescribing information for instructions on conversion, titration, and maintenance of therapy. (2.3, 2.4) For patients converting from other opioid analgesics, discontinue all opioid analgesics other than as needed for breakthrough pain and initiate tramadol hydrochloride extended-release tablets at a dose of 100 mg once daily, then titrate up by 100 mg increments every 5 days according to need and tolerance. (2.3, 2.4) Do not exceed a daily dose of 300 mg tramadol. Do not use with other tramadol products. (2.4) Periodically reassess patients receiving tramadol hydrochloride extended-release tablets to evaluate the continued need for opioid analgesics to maintain pain control, for the signs or symptoms of adverse reactions, and for the development of addiction, abuse, or misuse. (2.4) Do not rapidly reduce or abruptly discontinue tramadol hydrochloride extended-release tablets in a physically-dependent patient because rapid reduction or abrupt discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. (2.5, 5.18) 2.1 Important Dosage and Administration Instructions Tramadol hydrochloride extended-release tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. Do not use tramadol hydrochloride extended-release tablets concomitantly with other tramadol products [see Warnings and Precautions (5.3), (5.15)]. Do not administer tramadol hydrochloride extended-release tablets at a dose exceeding 300 mg per day. Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [see Warnings and Precautions (5)] . Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of tramadol hydrochloride extended-release tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Initiate the dosing regimen for each patient individually, taking into account the patient's underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse [see Warnings and Precautions (5.1)] Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with tramadol hydrochloride extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments [see Warnings and Precautions (5)] . Tramadol hydrochloride extended-release tablets should be taken once daily, at approximately the same time every day. Instruct patients to swallow tramadol hydrochloride extended-release tablets whole [see Patient Counseling Information (17)], and to take it with liquid. Crushing, chewing, splitting, or dissolving tramadol hydrochloride extended-release tablets will result in uncontrolled delivery of tramadol and can lead to overdose or death [see Warnings and Precautions (5.1)] . Tramadol hydrochloride

6 ADVERSE REACTIONS The following serious or otherwise important adverse reactions are described in greater detail, in other sections: Addiction, Abuse, and Misuse [see Warnings and Precautions (5.1)] Life-Threatening Respiratory Depression [see Warnings and Precautions (5.2)] Ultra-Rapid Metabolism of Tramadol and Other Risk Factors for Life-Threatening Respiratory Depression in Children [see Warnings and Precautions (5.6)] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions (5.4)] Interactions with Benzodiazepines and Other CNS Depressants [see Warnings and Precautions (5.3)] Opioid-Induced Hyperalgesia and Allodynia [See Warnings and Precautions (5.8)] Serotonin Syndrome [see Warnings and Precautions (5.9)] Seizures [see Warnings and Precautions (5.10)] Suicide [see Warnings and Precautions (5.11)] Adrenal Insufficiency [see Warnings and Precautions (5.13)] Severe Hypotension [see Warnings and Precautions (5.14)] Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.16)] Hypersensitivity Reactions [see Warnings and Precautions (5.17)] Withdrawal [see Warnings and Precautions (5.18)] Most common adverse reactions (≥10% and ≥2 x placebo rate): Dizziness, constipation, nausea, headache, somnolence, flushing, pruritus, vomiting, insomnia, dry mouth. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sun Pharmaceutical Industries, Inc. at 1-800-818-4555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Tramadol hydrochloride extended-release tablets were administered to a total of 3108 patients during studies conducted in the U.S. These included four double-blind studies in patients with osteoarthritis and/or chronic low back pain and one open-label study in patients with chronic non-malignant pain. A total of 901 patients were 65 years or older. The frequency of adverse reactions generally increased with doses from 100 mg to 400 mg in the two pooled, twelve-week, randomized, double-blind, placebo-controlled studies in patients with chronic non-malignant pain (see Table 1). The most common adverse reactions from Table 1 occurring in ≥10% and ≥2 x placebo rate of the patients treated with tramadol hydrochloride extended-release tablets are dizziness (not vertigo), nausea, constipation, headache, somnolence, flushing, pruritus, vomiting, insomnia, and dry mouth. Table 1: Incidence (%) of patients with adverse reaction rates ≥ 5% from two 12-week placebo-controlled studies in patients with moderate to moderately severe chronic pain by dose (N=1811). MedDRA Preferred Term Tramadol Hydrochloride Extended-Release Tablets Placebo 100 mg (N=403) n (%) 200 mg (N=400) n (%) 300 mg (N=400) n (%) 400 mg (N=202) n (%) (N=406) n (%) Dizziness (not vertigo) 64 (16) 81 (20) 90 (23) 57 (28) 28 (7) Nausea 61 (15) 90 (23) 102 (26) 53 (26) 32 (8) Constipation 49 (12) 68 (17) 85 (21) 60 (30) 17 (4) Headache 49 (12) 62 (16) 46 (12) 32 (16) 43 (11) Somnolence 33 (8) 45 (11) 29 (7) 41 (20) 7 (2) Flushing 31 (8) 40 (10) 35 (9) 32 (16) 18 (4) Pruritus 25 (6) 34 (9) 30 (8) 24 (12) 4 (1) Vomiting 20 (5) 29 (7) 34 (9) 19 (9) 11 ( 3) Insomnia 26 (7) 32 (8) 36 (9) 22 (11) 13 (3) Dry Mouth 20 (5) 29 (7) 39 (10) 18 (9) 6 (2) Diarrhea 15 (4) 27 (7) 37 (9) 10 (5) 17 (4) Asthenia 14 (4) 24 (6) 26 (7) 13 (6) 7 (2) Postural hypotension 7 (2) 17 (4) 8 (2) 11 (5) 9 (2) Sweating increased 6 (2) 8 (2) 15 (4) 13 (6) 1 (0) Anorexia 3 (1) 7 (2) 21 (5) 12 (6) 1 (0) Adverse reactions With Incidence Rates of 1.0% to <5.0% During Clinical Trials The following adverse reactions were reported from all the chronic pain studies (N=3108). The lists below include adverse reactions not otherwise noted in Table 1. Eye disorders: vision blurred Gastrointestinal disorders: abdominal pain upper, dyspepsia, abdominal pain, sore throat General disorders: weakness, pain, feeling hot, influenza like illness, fall, rigors, lethargy, pyrexia, chest pain Infections and infestations: nasopharyngitis, upper respiratory tract infection, sinusitis, influenza, gastroenteritis viral, urinary tract infection, bronchitis Investigations: blood creatine phosphokinase increased, weight decreased Metabolism and nutrition disorders: appetite decreased Musculoskeletal, connective tissue and bone disorders: arthralgia, back pain, pain in limb, neck pain Nervous system disorders: tremor, paresthesia, hypoesthesia Psychiatric disorders: nervousness, anxiety, depression, restlessness Respiratory, thoracic and mediastinal disorders: sneezing, cough, rhinorrhea, nasal congestion, dyspnea, sinus congestion Skin and subcutaneous tissue disorders: sweating increased, dermatitis Vascular disorders: hot flushes, vasodilatation Adverse Reactions With Incidence Rates of 0.5% to <1

7 DRUG INTERACTIONS Table 2 includes clinically significant drug interactions with tramadol hydrochloride extended-release tablets. Table 2: Clinically Significant Drug Interactions with Tramadol Hydrochloride Extended-Release Tablets Inhibitors of CYP2D6 Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP2D6 inhibitors may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. Since M1 is a more potent µ-opioid agonist, decreased M1 exposure could result in decreased therapeutic effects, and may result in signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Increased tramadol exposure can result in increased or prolonged therapeutic effects and increased risk for serious adverse events including seizures and serotonin syndrome. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease and the M1 plasma concentration will increase which could increase or prolong therapeutic effects but also increase adverse reactions related to opioid toxicity, and may cause potentially fatal respiratory depression [see Clinical Pharmacology ( 12.3 )] . Intervention: If concomitant use of a CYP2D6 inhibitor is necessary, evaluate patients at frequent intervals for adverse reactions including opioid withdrawal, seizures, and serotonin syndrome. If a CYP2D6 inhibitor is discontinued, consider lowering tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients at frequent intervals for adverse events including respiratory depression and sedation. Examples Quinidine, fluoxetine, paroxetine and bupropion Inhibitors of CYP3A4 Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inhibitors can increase the plasma concentration of tramadol and may result in a greater amount of metabolism via CYP2D6 and greater levels of M1. Follow patients closely for increased risk of serious adverse events including seizures and serotonin syndrome, and adverse reactions related to opioid toxicity including potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the tramadol plasma concentration will decrease [see Clinical Pharmacology ( 12.3 )] , resulting in decreased opioid efficacy and possibly signs and symptoms of opioid withdrawal in patients who had developed physical dependence to tramadol. Intervention: If concomitant use is necessary, consider dosage reduction of tramadol hydrochloride extended-release tablets until stable drug effects are achieved. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of seizures, serotonin syndrome, and signs of respiratory depression and sedation. Evaluate patients at frequent intervals for seizures and serotonin syndrome, and signs of respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved and evaluate patients at frequent intervals for signs and symptoms of opioid withdrawal. Examples Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology ( 12.3 )] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol, [see Warnings and Precautions ( 5. 7)] . After stopping a CYP3A4 inducer, as the effects of the inducer decline, the tramadol plasma concentration will increase [see Clinical Pharmacology ( 12.3 )] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause seizures and serotonin syndrome, and potentially fatal respiratory depression. Intervention: If concomitant use is necessary, consider increasing the tramadol hydrochloride extended-release tablets dosage until stable drug effects are achieved. Evaluate patients for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider tramadol hydrochloride extended-release tablets dosage reduction and evaluate patients at frequent intervals for seizures and serotonin syndrome, and signs of respiratory depression and sedation. Patients taking carbamazepine, a CYP3A4 inducer, may have a significantly reduced analgesic effect of tramadol. Because carbamazepine increa