Carbidopa and Levodopa

1 INDICATIONS AND USAGE Carbidopa and levodopa extended-release capsules are indicated for the treatment of Parkinson's disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication or manganese intoxication. Carbidopa and levodopa extended-release capsule is a combination of carbidopa (an aromatic amino acid decarboxylation inhibitor) and levodopa (an aromatic amino acid) indicated for the treatment of Parkinson's disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication or manganese intoxication ( 1 )

2 DOSAGE AND ADMINISTRATION Levodopa-naïve patients: Starting dose is 23.75 mg / 95 mg three times daily; may increase to 36.25 mg / 145 mg three times daily on the fourth day of treatment ( 2.1 ) See Table 1 for instructions for converting patients taking immediate-release carbidopa-levodopa to an initial dose of carbidopa and levodopa extended-release capsules. Dosages of carbidopa and levodopa extended-release capsules are not interchangeable with other carbidopa-levodopa products ( 2.2 ) The maximum recommended daily dose of carbidopa and levodopa extended-release capsules is 612.5 mg/2,450 mg ( 2.1 , 2.2 ) Carbidopa and levodopa extended-release capsules may be taken with or without food; do not chew, divide or crush ( 2.4 , 12.3 ) 2.1 Dosage in Patients Naïve to Levodopa Therapy The recommended starting dosage of carbidopa and levodopa extended-release capsules in levodopa-naïve patients is 23.75 mg/95 mg taken orally three times a day for the first 3 days. On the fourth day of treatment, the dosage of carbidopa and levodopa extended-release capsules may be increased to 36.25 mg/145 mg taken three times a day. Based upon individual patient clinical response and tolerability, the carbidopa and levodopa extended-release capsules dose may be increased up to a maximum recommended dose of 97.5 mg/390 mg taken three times a day. The dosing frequency may be changed from three times a day to a maximum of five times a day if more frequent dosing is needed and if tolerated. Maintain patients on the lowest dosage required to achieve symptomatic control and to minimize adverse reactions such as dyskinesia and nausea. The maximum recommended daily dose of carbidopa and levodopa extended-release capsules is 612.5 mg/2,450 mg. 2.2 Converting from Immediate-Release Carbidopa-Levodopa to Carbidopa and Levodopa Extended-Release Capsules The dosages of other carbidopa and levodopa products are not interchangeable on a 1:1 basis with the dosages of carbidopa and levodopa extended-release capsules. To convert patients from immediate-release carbidopa-levodopa to carbidopa and levodopa extended-release capsules, first calculate the patient's current total daily dose of levodopa. The starting total daily dose of carbidopa and levodopa extended-release capsules is as recommended in Table 1. After conversion, any combination of the four carbidopa and levodopa extended-release capsules dosage strengths can be used to achieve an optimal dosing. Adjust the dose and dosing frequency as necessary to maintain patient tolerance and sufficient symptomatic control. Administration of concomitant Parkinson's disease medications should remain stable while adjusting the carbidopa and levodopa extended-release capsules dose. In clinical trials, carbidopa and levodopa extended-release capsules were administered in divided doses of three to five times a day. The maximum recommended total daily dose of carbidopa and levodopa extended-release capsule is 612.5 mg/2,450 mg. For patients currently treated with carbidopa and levodopa plus a catechol-O-methyl transferase (COMT) inhibitor (such as entacapone), the initial total daily dose of levodopa in carbidopa and levodopa extended-release capsules described in Table 1 may need to be increased. Use of carbidopa and levodopa extended-release capsules in combination with other levodopa products has not been studied. Table 1 Conversion from Immediate-Release Carbidopa-Levodopa to Carbidopa and Levodopa Extended-Release Capsules Total Daily Dose of Levodopa in Immediate-Release Carbidopa- Levodopa Recommended Starting Dosage of Carbidopa and Levodopa Extended-Release Capsules Total Daily Dose of Levodopa in Carbidopa and Levodopa Extended-Release Capsules Carbidopa and Levodopa Extended-Release Capsules Dosing Regimen 400 mg to 549 mg 855 mg 3 capsules carbidopa and levodopa extended-release capsules 23.75 mg/95 mg taken TID a 550 mg to 749 mg 1,140 mg 4 capsules carbidopa and levodopa extended-release capsules 23.75 mg…

5 WARNINGS AND PRECAUTIONS May cause falling asleep during activities of daily living ( 5.1 ) Avoid sudden discontinuation or rapid dose reduction to reduce the risk of withdrawal-emergent hyperpyrexia and confusion ( 5.2 ) Cardiovascular Events: Monitor patients with a history of cardiovascular disease ( 5.3 ) Hallucinations/Psychosis may occur ( 5.4 ) Impulse Control Disorders: Consider dose reduction or stopping carbidopa and levodopa extended-release capsules if occurs ( 5.5 ) May cause or exacerbate dyskinesia: Consider dose reduction ( 5.6 ) 5.1 Falling Asleep During Activities of Daily Living and Somnolence Patients treated with levodopa, a component of carbidopa and levodopa extended-release capsules, have reported falling asleep while engaged in activities of daily living, including the operation of motor vehicles, which sometimes resulted in accidents. Although many of these patients reported somnolence while on levodopa, some perceived that they had no warning signs (sleep attack), such as excessive drowsiness, and believed that they were alert immediately prior to the event. Some of these events have been reported more than 1 year after initiation of treatment. It has been reported that falling asleep while engaged in activities of daily living usually occurs in a setting of pre-existing somnolence, although patients may not give such a history. For this reason, prescribers should reassess patients for drowsiness or sleepiness in carbidopa and levodopa extended-release capsules-treated patients, especially since some of the events occur well after the start of treatment. Prescribers should also be aware that patients may not acknowledge drowsiness or sleepiness until directly questioned about drowsiness or sleepiness during specific activities. Before initiating treatment with carbidopa and levodopa extended-release capsules, advise patients of the potential to develop drowsiness and specifically ask about factors that may increase the risk for somnolence with carbidopa and levodopa extended-release capsules such as concomitant sedating medications or the presence of a sleep disorder. Consider discontinuing carbidopa and levodopa extended-release capsules in patients who report significant daytime sleepiness or episodes of falling asleep during activities that require active participation (e.g., conversations, eating, etc.). If a decision is made to continue carbidopa and levodopa extended-release capsules, patients should be advised not to drive and to avoid other potentially dangerous activities that might result in harm if the patients become somnolent. There is insufficient information to establish that dose reduction will eliminate episodes of falling asleep while engaged in activities of daily living. 5.2 Withdrawal-Emergent Hyperpyrexia and Confusion A symptom complex that resembles neuroleptic malignant syndrome (characterized by elevated temperature, muscular rigidity, altered consciousness, and autonomic instability), with no other obvious etiology, has been reported in association with rapid dose reduction, withdrawal of, or changes in dopaminergic therapy. Avoid sudden discontinuation or rapid dose reduction in patients taking carbidopa and levodopa extended-release capsules. If the decision is made to discontinue carbidopa and levodopa extended-release capsules, the dose should be tapered to reduce the risk of hyperpyrexia and confusion [see Dosage and Administration ( 2.4 )] . 5.3 Cardiovascular Ischemic Events Cardiovascular ischemic events have occurred in patients taking carbidopa and levodopa extended-release capsules. In a placebo controlled clinical study in patients with early Parkinson's disease, 7/289 (2.4%) of carbidopa and levodopa extended-release capsules-treated patients experienced cardiovascular ischemic adverse reactions compared to 1/92 (1.1%) of placebo-treated patients. In an active-controlled clinical study in patients with advanced Parkinson's disease, 3/450 (0.7%) of carbidopa a…

4 CONTRAINDICATIONS Carbidopa and levodopa extended-release capsules are contraindicated in patients: Currently taking a nonselective monoamine oxidase (MAO) inhibitor (e.g., phenelzine and tranylcypromine) or have recently (within 2 weeks) taken a nonselective MAO inhibitor. Hypertension can occur if these drugs are used concurrently [see Drug Interactions ( 7.1 )] . Nonselective MAO inhibitors ( 4 )

7 DRUG INTERACTIONS Iron salts and dopamine D2 antagonists including metoclopramide: May reduce the effectiveness of carbidopa and levodopa extended-release capsules ( 7.2 , 7.3 ) 7.1 Monoamine Oxidase (MAO) Inhibitors The use of nonselective MAO inhibitors with carbidopa and levodopa extended-release capsules is contraindicated [see Contraindications ( 4 )] . Discontinue use of any nonselective MAO inhibitors at least two weeks prior to initiating carbidopa and levodopa extended-release capsules. The use of selective MAO-B inhibitors (e.g., rasagiline and selegiline) with carbidopa and levodopa extended-release capsules may be associated with orthostatic hypotension. Monitor patients who are taking these drugs concurrently. 7.2 Dopamine D2 Receptor Antagonists and Isoniazid Dopamine D2 receptor antagonists (e.g., phenothiazines, butyrophenones, risperidone, metoclopramide) and isoniazid may reduce the effectiveness of levodopa. Monitor patients for worsening Parkinson's symptoms. 7.3 Iron Salts Iron salts or multivitamins containing iron salts can form chelates with levodopa and carbidopa and can cause a reduction in the bioavailability of carbidopa and levodopa extended-release capsules. If iron salts or multivitamins containing iron salts are co-administered with carbidopa and levodopa extended-release capsules, monitor patients for worsening Parkinson's symptoms.

8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of carbidopa and levodopa extended-release capsules in pregnant women. In animal studies, carbidopa-levodopa has been shown to be developmentally toxic (including teratogenic effects) at clinically relevant doses (see Data) . The estimated background risk of major birth defects and miscarriage in the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data When administered to pregnant rabbits throughout organogenesis, carbidopa-levodopa caused both visceral and skeletal malformation in fetuses at all doses and ratios of carbidopa-levodopa tested. No teratogenic effects were observed when carbidopa-levodopa was administered to pregnant mice throughout organogenesis. There was a decrease in the number of live pups delivered by rats receiving carbidopa-levodopa during organogenesis.

8.2 Lactation Risk Summary Levodopa has been detected in human milk after administration of carbidopa-levodopa. There are no data on the presence of carbidopa in human milk, the effects of levodopa or carbidopa on the breastfed infant, or the effects on milk production. However, inhibition of lactation may occur because levodopa decreases secretion of prolactin in humans. Carbidopa is excreted in rat milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for carbidopa and levodopa extended-release capsules and any potential adverse effects on the breastfed infant from carbidopa and levodopa extended-release capsules or from the underlying maternal condition.

6 ADVERSE REACTIONS The following serious adverse reactions are discussed below and elsewhere in the labeling: Falling Asleep During Activities of Daily Living and Somnolence [see Warnings and Precautions ( 5.1 )] Withdrawal-Emergent Hyperpyrexia and Confusion [see Warnings and Precautions ( 5.2 )] Cardiovascular Ischemic Events [see Warnings and Precautions ( 5.3 )] Hallucinations/Psychosis [see Warnings and Precautions ( 5.4 )] Impulse Control/Compulsive Behaviors [see Warnings and Precautions ( 5.5 )] Dyskinesia [see Warnings and Precautions ( 5.6 )] Peptic Ulcer Disease [see Warnings and Precautions ( 5.7 )] Glaucoma [see Warnings and Precautions ( 5.8 )] Early Parkinson's disease: Most common adverse reactions (incidence ≥ 5% and greater than placebo) are nausea, dizziness, headache, insomnia, abnormal dreams, dry mouth, dyskinesia, anxiety, constipation, vomiting, and orthostatic hypotension ( 6.1 ) Advanced Parkinson's disease: Most common adverse reactions (incidence ≥ 5% and greater than oral immediate-release carbidopa-levodopa) are nausea and headache ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc. at 1-877-993-8779 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 clinical practice. The safety population consisted of a total of 978 Parkinson's disease patients who received at least one dose of carbidopa and levodopa extended-release capsules, and had an average duration of exposure of 40 weeks. Adverse Reactions in Early Parkinson's Disease In a placebo-controlled clinical study in patients with early Parkinson's disease (Study 1), the most common adverse reactions with carbidopa and levodopa extended-release capsules (in at least 5% of patients and more frequently than in placebo) were nausea, dizziness, headache, insomnia, abnormal dreams, dry mouth, dyskinesia, anxiety, constipation, vomiting, and orthostatic hypotension. Table 2 lists adverse reactions occurring in at least 5% of carbidopa and levodopa extended-release capsules-treated patients and at a higher rate than placebo in Study 1. Table 2 Adverse Reactions in Study 1 in Patients with Early Stage Parkinson's Disease Placebo Carbidopa and Levodopa Extended-release Capsules 36.25 mg Carbidopa Carbidopa and Levodopa Extended-release Capsules 61.25 mg Carbidopa Carbidopa and Levodopa Extended-release Capsules 97.5 mg Carbidopa 145 mg Levodopa TID 245 mg Levodopa TID 390 mg Levodopa TID (N=92) (N=87) (N=104) (N=98) % % % % Nausea 9 14 19 20 Dizziness 5 9 19 12 Headache 11 7 13 17 Insomnia 3 2 9 6 Abnormal Dreams 0 2 6 5 Dry Mouth 1 3 2 7 Dyskinesia 0 2 4 5 Anxiety 0 2 3 5 Constipation 1 2 6 2 Vomiting 3 2 2 5 Orthostatic Hypotension 1 1 1 5 Adverse Reactions Leading to Discontinuation in Study 1 In Study 1, 12% of patients discontinued carbidopa and levodopa extended-release capsules early due to adverse reactions; a higher proportion of patients in the 61.25 mg/ 245 mg carbidopa and levodopa extended-release capsules-treated group (14%) and in the 97.5 mg/390 mg carbidopa and levodopa extended-release capsules-treated group (15%) experienced adverse reactions leading to early discontinuation compared to (4%) in the placebo group. The most common adverse reactions resulting in early discontinuation were nausea, dizziness, and vomiting. Adverse Reactions in Advanced Parkinson's Disease In an active-controlled clinical study in patients with advanced Parkinson's disease (Study 2), the most common adverse reactions with carbidopa and levodopa extended-release capsules that occurred during dose conversion or maintenance (in at least 5% of patients and more frequently than on oral immediate-release carbidopa-levodopa) were nausea and headache. …