Lyrica CR (Page 6 of 9)

8.4 Pediatric Use

The safety and effectiveness of LYRICA CR in pediatric patients have not been established.

Juvenile Animal Toxicity Data

In studies in which pregabalin (50 to 500 mg/kg) was orally administered to young rats from early in the postnatal period (Postnatal Day 7) through sexual maturity, neurobehavioral abnormalities (deficits in learning and memory, altered locomotor activity, decreased auditory startle responding and habituation) and reproductive impairment (delayed sexual maturation and decreased fertility in males and females) were observed at doses greater than or equal to 50 mg/kg. The neurobehavioral changes of acoustic startle persisted at greater than or equal to 250 mg/kg and locomotor activity and water maze performance at greater than or equal to 500 mg/kg in animals tested after cessation of dosing and, thus, were considered to represent long-term effects. The low effect dose for developmental neurotoxicity and reproductive impairment in juvenile rats (50 mg/kg) was associated with a plasma pregabalin exposure (AUC) approximately equal to human exposure at the maximum recommended dose of 660 mg/day. A no-effect dose was not established.

8.5 Geriatric Use

In controlled clinical studies of LYRICA in neuropathic pain associated with diabetic peripheral neuropathy, 246 patients were 65 to 74 years of age, and 73 patients were 75 years of age or older.

In controlled clinical studies of LYRICA in neuropathic pain associated with postherpetic neuralgia, 282 patients were 65 to 74 years of age, and 379 patients were 75 years of age or older.

In the LYRICA CR neuropathic pain associated with postherpetic neuralgia study, 422 patients 65 years of age and older received pregabalin.

No overall differences in safety and effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Pregabalin is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. See Dosage and Administration (2.5) for recommendations for dosing in patients with renal impairment.

9 DRUG ABUSE AND DEPENDENCE

9.1 Controlled Substance

LYRICA CR contains pregabalin, a Schedule V controlled substance.

9.2 Abuse

In a study of recreational users (N=15) of sedative/hypnotic drugs, including alcohol, LYRICA (450 mg, single dose) received subjective ratings of “good drug effect,” “high” and “liking” to a degree that was similar to diazepam (30 mg, single dose). In controlled clinical studies in over 5500 patients, 4% of LYRICA-treated patients and 1% of placebo-treated patients overall reported euphoria as an adverse reaction, though in some patient populations studied, this reporting rate was higher and ranged from 1 to 12%.

Carefully evaluate all patients treated with LYRICA CR for history of drug abuse and observe them for signs of LYRICA CR misuse or abuse (e.g., development of tolerance, dose escalation, drug-seeking behavior).

9.3 Dependence

In clinical studies, following abrupt or rapid discontinuation of LYRICA CR, some patients reported symptoms including insomnia, nausea, headache diarrhea, or anxiety [see Warnings and Precautions (5.6)] , consistent with physical dependence. In the postmarketing experience with LYRICA, in addition to these reported symptoms there have also been reported cases of hyperhidrosis.

10 OVERDOSAGE

Signs, Symptoms and Laboratory Findings of Acute Overdosage in Humans

In the postmarketing experience, the most commonly reported adverse events observed with pregabalin when taken in overdose include reduced consciousness, depression/anxiety, confusional state, agitation, and restlessness. Seizures and heart block have also been reported. Deaths have been reported in the setting of lone LYRICA overdose and in combination with other CNS depressants.

Treatment or Management of Overdose

There is no specific antidote for overdose with pregabalin. If indicated, elimination of unabsorbed drug may be attempted by emesis or gastric lavage; observe usual precautions to maintain the airway. General supportive care of the patient is indicated including monitoring of vital signs and observation of the clinical status of the patient. Contact a Certified Poison Control Center for up-to-date information on the management of overdose with pregabalin.

Pregabalin can be removed by hemodialysis. Standard hemodialysis procedures result in significant clearance of pregabalin (approximately 50% in 4 hours).

11 DESCRIPTION

LYRICA CR (pregabalin extended-release) tablets are for oral use and contain pregabalin. Pregabalin is described chemically as (S)-3-(aminomethyl)-5-methylhexanoic acid. The molecular formula is C8 H17 NO2 and the molecular weight is 159.23. The chemical structure of pregabalin is:

Chemical Structure

Pregabalin is a white to off-white, crystalline solid with a pKa1 of 4.2 and a pKa2 of 10.6. It is freely soluble in water and both basic and acidic aqueous solutions. The log of the partition coefficient (n-octanol/0.05M phosphate buffer) at pH 7.4 is – 1.35.

LYRICA CR extended-release tablets are administered orally and contain 82.5, 165, or 330 mg of pregabalin, along with Kollidon SR (polyvinyl acetate, povidone, sodium lauryl sulphate, and silica), crospovidone, polyethylene oxide, carbomer, magnesium stearate, polyvinyl alcohol, titanium dioxide, talc, polyethylene glycol, and colorants as inactive ingredients.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Pregabalin binds with high affinity to the alpha2 -delta site (an auxiliary subunit of voltage-gated calcium channels) in central nervous system tissues. Although the mechanism of action of pregabalin has not been fully elucidated, results with genetically modified mice and with compounds structurally related to pregabalin (such as gabapentin) suggest that binding to the alpha2 -delta subunit may be involved in pregabalin’s anti-nociceptive and antiseizure effects in animals. In animal models of nerve damage, pregabalin has been shown to reduce calcium-dependent release of pro-nociceptive neurotransmitters in the spinal cord, possibly by disrupting alpha2 -delta containing-calcium channel trafficking and/or reducing calcium currents. Evidence from other animal models of nerve damage and persistent pain suggest the anti-nociceptive activities of pregabalin may also be mediated through interactions with descending noradrenergic and serotonergic pathways originating from the brainstem that modulate pain transmission in the spinal cord.

While pregabalin is a structural derivative of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), it does not bind directly to GABAA , GABAB , or benzodiazepine receptors, does not augment GABAA responses in cultured neurons, does not alter rat brain GABA concentration or have acute effects on GABA uptake or degradation. However, in cultured neurons prolonged application of pregabalin increases the density of GABA transporter protein and increases the rate of functional GABA transport. Pregabalin does not block sodium channels, is not active at opiate receptors, and does not alter cyclooxygenase enzyme activity. It is inactive at serotonin and dopamine receptors and does not inhibit dopamine, serotonin, or noradrenaline reuptake.

12.3 Pharmacokinetics

LYRICA CR has linear pharmacokinetics with dose-proportional increases in maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve (AUC) from 82.5–660 mg/day. Following repeated administration, steady state is achieved within approximately 48–72 hours.

LYRICA CR administered once daily following an evening meal has equivalent AUC and lower Cmax relative to a comparative dose of LYRICA administered without food twice daily (Table 5). Variability in Cmax and AUC for LYRICA CR is less than or equal to 25%.

Table 5. Steady-State Pharmacokinetics for LYRICA CR 165 mg Once Daily and LYRICA 75 mg Twice Daily
LYRICA CR Once Daily LYRICA BID
Note: Geometric mean (%CV) for AUC24 , Cmax , Cmin ; median (range) for Tmax .Abbreviations: AUC24 =area under the curve over 24 hours; BID=every 12 hours; Cmax =peak concentrations; Cmin =minimum concentrations; N=Number of subjects ; Tmax =time to peak concentrations.

N

24

24

Cmax (µg/mL)

2.0 (17)

3.2 (21)

Tmax (h)

8.0 (5.0 – 12.0)

0.7 (0.7 – 1.5)

AUC24 (µg∙h/mL)

29.4 (17)

31.5 (18)

Cmin (µg/mL)

0.44 (24)

0.59 (25)

Absorption

Pregabalin is absorbed from the small intestine and proximal colon. LYRICA CR absorption is linear and dose proportional.

The bioavailability of LYRICA CR is reduced if taken on an empty stomach. The AUC is approximately 30% lower when LYRICA CR is administered fasted relative to following an evening meal.

When LYRICA CR is administered following a 600 to 750 calorie (50% carbohydrates, 20% protein, 30% fat) evening meal, peak plasma concentrations occur within approximately 8 to 10 hours and AUC is approximately 93% to 97% relative to a comparative dose of LYRICA. The rate and extent of LYRICA CR absorption is similar when administered following a 400 to 500 calorie, 30% fat or an 800 to 1000 calorie, 15%, 30%, or 50% fat evening meal.

When LYRICA CR is administered following an 800 to 1000 calorie (50% carbohydrates, 20% protein, 30% fat) morning meal, peak plasma concentrations occur within approximately 12 hours and AUC is 99% relative to a comparative dose of LYRICA. AUC decreases approximately 13% to 25% when LYRICA CR is administered following a 400 to 500 calorie or 600 to 750 calorie (50% carbohydrates, 20% protein, 30% fat) morning meal relative to the 800 to 1000 calorie meal, while Cmax remains the same.

Distribution

Pregabalin does not bind to plasma proteins. The apparent volume of distribution of pregabalin following oral administration is approximately 0.5 L/kg. Pregabalin is a substrate for system L transporter which is responsible for the transport of large amino acids across the blood brain barrier. Although there are no data in humans, pregabalin has been shown to cross the blood brain barrier in mice, rats, and monkeys. In addition, pregabalin has been shown to cross the placenta in rats and is present in the milk of lactating rats.

Elimination

Metabolism

Pregabalin undergoes negligible metabolism in humans. Following a dose of radiolabeled pregabalin, approximately 90% of the administered dose was recovered in the urine as unchanged pregabalin. The N-methylated derivative of pregabalin, the major metabolite of pregabalin found in urine, accounted for 0.9% of the dose. In preclinical studies, pregabalin (S-enantiomer) did not undergo racemization to the R-enantiomer in mice, rats, rabbits, or monkeys.

Excretion

Pregabalin is eliminated from the systemic circulation primarily by renal excretion as unchanged drug with a mean elimination half-life of 6.3 hours in subjects with normal renal function. Mean renal clearance was estimated to be 67.0 to 80.9 mL/min in young healthy subjects. Because pregabalin is not bound to plasma proteins this clearance rate indicates that renal tubular reabsorption is involved. Pregabalin elimination is nearly proportional to CLcr [see Dosage and Administration (2.5)].

Specific Populations

Age: Geriatric Patients

Pregabalin oral clearance tended to decrease with increasing age. This decrease in pregabalin oral clearance is consistent with age-related decreases in CLcr. Reduction of pregabalin dose may be required in patients who have age-related compromised renal function [see Dosage and Administration (2.5)].

Sex

Population pharmacokinetic analyses of the clinical studies showed that the relationship between daily dose and LYRICA CR drug exposure is similar between genders.

Race/Ethnicity

In population pharmacokinetic analyses of the clinical studies of LYRICA and LYRICA CR, the pharmacokinetics of pregabalin were not significantly affected by race (Caucasians, Blacks, and Hispanics).

Renal Impairment

Pregabalin clearance is nearly proportional to CLcr. Dosage reduction in patients with reduced renal function is necessary. Pregabalin is effectively removed from plasma by hemodialysis. Following a 4-hour hemodialysis treatment, plasma pregabalin concentrations are reduced by approximately 50%. For patients on hemodialysis, treatment with LYRICA CR is not recommended [see Dosage and Administration (2.5)].

Drug Interaction Studies

In Vitro Studies

In vitro studies showed that pregabalin is unlikely to be involved in significant pharmacokinetic drug interactions. Pregabalin, at concentrations that were, in general, 10-times those attained in clinical trials, does not inhibit human CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 enzyme systems. In vitro drug interaction studies demonstrate that pregabalin does not induce CYP1A2 or CYP3A4 activity. Therefore, an increase in the metabolism of co-administered CYP1A2 substrates (e.g., theophylline, caffeine) or CYP3A4 substrates (e.g., midazolam, testosterone) is not anticipated.

In Vivo Studies

With the exception of erythromycin, the interactions of LYRICA CR with co-administration of other drugs have not been systematically evaluated.

Additional studies have been performed with LYRICA [see Drug Interactions (7)]. No pharmacokinetic interactions were observed between LYRICA and carbamazepine, ethanol, gabapentin, lamotrigine, lorazepam, oral contraceptive, oxycodone, phenobarbital, phenytoin, topiramate, and valproic acid. A similar lack of pharmacokinetic interactions would be expected to occur with LYRICA CR.

The drug interaction studies described in this section were conducted in healthy adults, and across various patient populations.

Erythromycin

Multiple-dose administration of erythromycin (500 mg every 6 hours for 18 hours) in healthy subjects resulted in a 17% decrease in AUC of LYRICA CR (330 mg single dose).

Ethanol

Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of ethanol single-dose pharmacokinetics and single-dose administration of ethanol (0.7 g/kg) had no effect on the steady-state pharmacokinetics of pregabalin. Additive effects on cognitive and gross motor functioning were seen when LYRICA was co-administered with ethanol. No clinically important effects on respiration were seen [see Drug Interactions (7)].

Gabapentin

The pharmacokinetic interactions of pregabalin and gabapentin were investigated in 12 healthy subjects following concomitant single-dose administration of 100-mg pregabalin and 300-mg gabapentin and in 18 healthy subjects following concomitant multiple-dose administration of 200-mg pregabalin every 8 hours and 400-mg gabapentin every 8 hours. Gabapentin pharmacokinetics following single- and multiple-dose administration were unaltered by pregabalin co-administration. The extent of pregabalin absorption was unaffected by gabapentin co-administration, although there was a small reduction in rate of absorption.

Lorazepam

Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of lorazepam single-dose pharmacokinetics and single-dose administration of lorazepam (1 mg) had no effect on the steady-state pharmacokinetics of pregabalin. Additive effects on cognitive and gross motor functioning were seen when LYRICA was co-administered with lorazepam. No clinically important effects on respiration were seen [see Drug Interactions (7)].

Oral Contraceptive

Pregabalin co-administration (200 mg 3 times a day) had no effect on the steady-state pharmacokinetics of norethindrone and ethinyl estradiol (1 mg/35 µg, respectively) in healthy subjects.

Oxycodone

Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of oxycodone single-dose pharmacokinetics. Single-dose administration of oxycodone (10 mg) had no effect on the steady-state pharmacokinetics of pregabalin. Additive effects on cognitive and gross motor functioning were seen when LYRICA was co-administered with oxycodone. No clinically important effects on respiration were seen [see Drug Interactions (7)].

Carbamazepine, Lamotrigine, Phenobarbital, Phenytoin, Topiramate and Valproic Acid

Steady-state trough plasma concentrations of phenytoin, carbamazepine, and carbamazepine 10,11 epoxide, valproic acid, and lamotrigine were not affected by concomitant pregabalin (200 mg 3 times a day) administration.

Population pharmacokinetic analyses in patients treated with pregabalin and various concomitant medications suggest the following:

Therapeutic class Specific concomitant drug studied

Concomitant drug has no effect on the pharmacokinetics of pregabalin

Hypoglycemics

Glyburide, insulin, metformin

Diuretics

Furosemide

Antiepileptic Drugs

Tiagabine

Concomitant drug has no effect on the pharmacokinetics of pregabalin and pregabalin has no effect on the pharmacokinetics of concomitant drug

Antiepileptic Drugs

Carbamazepine, lamotrigine, phenobarbital, phenytoin, topiramate, valproic acid

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2024. All Rights Reserved.