Rexant

Rexant Uses, Dosage, Side Effects, Food Interaction and all others data.

Rexant is a short-acting drug for the management of spasticity. Rexant is an agonist at α2-adrenergic receptor sites and presumably reduces spasticity by increasing presynaptic inhibition of motor neurons. In animal models, tizanidine has no direct effect on skeletal muscle fibers or the neuromuscular junction, and no major effect on monosynaptic spinal reflexes. The effects of tizanidine are greatest on polysynaptic pathways. The overall effect of these actions is thought to reduce facilitation of spinal motor neurons.

A note on spasticity

Spasticity is an increase in muscle accompanied by uncontrolled, repetitive contractions of skeletal muscles which are involuntary.The patient suffering from muscle spasticity may have reduced mobility and high levels of pain, contributing to poor quality of life and problems performing activities of personal hygiene and care .

General effects

Trade Name Rexant
Availability Prescription only
Generic Tizanidine
Tizanidine Other Names Tizanidin, Tizanidina, Tizanidine, Tizanidinum
Related Drugs cyclobenzaprine, diazepam, methocarbamol, Flexeril, Valium, Soma
Weight 2mg
Type Tablet
Formula C9H8ClN5S
Weight Average: 253.711
Monoisotopic: 253.018893678
Protein binding

About 30% bound to plasma proteins .

Groups Approved, Investigational
Therapeutic Class Centrally acting Skeletal Muscle Relaxants
Manufacturer Helix Pharma (private) Limited
Available Country Pakistan
Last Updated: September 19, 2023 at 7:00 am
Rexant
Rexant

Uses

It is used in the symptomatic treatment of painful muscle spasm associated with musculoskeletal conditions and as an adjunct in the management of spasticity associated with multiple sclerosis or spinal cord disorders.

Rexant is also used to associated treatment for these conditions: Acute Low Back Pain, Drug Withdrawal Headache, Insomnia, Migraine, Pain, Seizures, Spasticity, Muscle, Withdrawal From Addictive Substance; Detoxification

How Rexant works

Rexant reduces spasticity by causing presynaptic inhibition of motor neurons via agonist actions at Alpha-2 adrenergic receptor sites. This drug is centrally acting and leads to a reduction in the release of excitatory amino acids like glutamate and aspartate, which cause neuronal firing that leads to muscle spasm. The above reduction and excitatory neurotransmitter release results in presynaptic inhibition of motor neurons. The strongest effect of tizanidine has been shown to occur on spinal polysynaptic pathways. The anti-nociceptive and anticonvulsant activities of tizanidine may also be attributed to agonist action on Alpha-2 receptors. Rexant also binds with weaker affinity to the Alpha-1 receptors, explaining its slight and temporary effect on the cardiovascular system .

Dosage

Rexant dosage

The usual initial daily dose is 2 mg as a single dose. The daily dose may be increased thereafter according to response in steps of 2 mg at intervals of at least 3 to 4 days, usually up to 24 mg daily given in 3 to 4 divided doses. The maximum recommended dose is 36 mg daily.

Side Effects

Rexant Hydrochloride may cause drowsiness, fatigue, dizziness, dry mouth, nausea, gastrointestinal disturbances, hypotension. Bradycardia, insomnia, hallucinations and altered liver enzymes, and rarely acute hepatitis have also been reported.

Toxicity

LD50 information

Oral LD50 (rat): 414 mg/kg; Subcutaneous LD50 (rat): 282 mg/kg; Oral LD50 (mouse): 235 mg/kg

Use in pregnancy

Animal studies have determined that this drug causes fetal harm . Studies have not been performed in humans, and it is advisable to ensure that tizanidine use in pregnant women should be reserved for cases in which possible benefit clearly outweighs the possible risk to mother and unborn child .

Use in breastfeeding

In studies of rat models, this tizanidine was found excreted in the breastmilk with a milk-to-blood ratio of 1.8:1 . In young nursing rats, abnormal results were obtained in tests indicative of central nervous system function. Various developmental changes that may have been attributable to the drug were observed. It is unknown whether tizanidine is excreted in human milk. It is a lipid-soluble drug, however, and likely to be excreted into breast milk .

Carcinogenesis and mutagenesis

No signs of carcinogenicity were observed in two dietary studies performed in rodent models. Rexant was given to mice for 78 weeks at doses reaching a maximum 16 mg/kg (equivalent to twice the maximum recommended human dose). In addition, the drug was given to rats for 104 weeks at doses reaching 9 mg/kg (equivalent to 2.5 times the maximum recommended human dose). There was a lack of a statistically significant increase in the occurrence of tumors in either study group .

Rexant was not found to be mutagenic or clastogenic in several laboratory essays, including the bacterial Ames test, the mammalian gene mutation test, in addition to the chromosomal aberration test in Chinese hamster cells and several other assays .

Precaution

Patients with impaired kidney or liver function; when patients drive a vehicle or operate machinery.

Interaction

Alcohol or other CNS depressants may enhance the CNS effects of Rexant. There may be an additive hypotensive effect when Rexant is used in patients receiving antihypertensive therapy.

Food Interaction

  • Avoid alcohol.
  • Take with or without food. Maintain the same schedule with regard to meals, as concentrations increase in the fasted state and decrease in the fed state.

Rexant Alcohol interaction

[Moderate]

The sedative effect of tizanidine may be potentiated by concomitant use of other agents with central nervous system (CNS) depressant effects.

In addition, tizanidine and many of these agents (e.g., alcohol, anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, muscle relaxants) also can exhibit hypotensive effects, which may be additive during coadministration and may increase the risk of symptomatic hypotension and orthostasis, particularly during initiation of therapy or dose escalation.

Rexant itself is a central alpha-2 adrenergic agonist.

Pharmacologic studies have found tizanidine to possess between 1/10 to 1/50 of the potency of clonidine, a structurally similar agent, in lowering blood pressure.

In a single-dose study where blood pressure was monitored closely after dosing, two-thirds of patients treated with an 8 mg dose had a 20% reduction in either the diastolic or systolic blood pressure.

The reduction was seen within 1 hour after dosing, peaked 2 to 3 hours after dosing, and was associated at times with bradycardia, orthostatic hypotension, lightheadedness, dizziness, and rarely, syncope.

The hypotensive effect of tizanidine is dose-related and has been measured following single doses of 2 mg or more.

Caution is advised and more gradual dose titration may be appropriate when tizanidine is used with other substances that can cause CNS depression and/or hypotension, particularly in elderly or debilitated patients.

Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to avoid rising abruptly from a sitting or recumbent position.

Patients should contact their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or excessive CNS effects that interfere with their normal activities.

Volume of Distribution

Extensively distributed throughout the body. The average steady-state volume of distribution is 2.4 L/kg .

Elimination Route

This drug undergoes significant first-pass metabolism. After the administration of an oral dose, tizanidine is mostly absorbed. The absolute oral bioavailability of tizanidine is measured to be about 40% .

Effect of food on absorption

Food has been shown to increase absorption for both the tablets and capsules. The increase in absorption with the tablet (about 30%) was noticeably higher than the capsule (~10%). When the capsule and tablet were administered with food, the amount absorbed from the capsule was about 80% of the amount absorbed from the tablet . It is therefore advisable to take this drug with food for increased absorption, especially in tablet form.

Half Life

Approximately 2.5 hours .

Clearance

A note on renal impairment

Rexant clearance is found to be decreased by more than 50% in elderly patients with renal insufficiency (creatinine clearance < 25 mL/min) compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. This drug should be used with caution in patients with renal impairment .

Elimination Route

This drug is mainly eliminated by the kidney .

Pregnancy & Breastfeeding use

Rexant has no teratogenic effects in rats and rabbits. As there have been no controlled studies in pregnant women, it should not be used during pregnancy unless the benefit clearly outweighs the risk. Although only small amounts of Rexant are excreted in animal milk, lactating women should not take Rexant.

Contraindication

Rexant Hydrochloride is contraindicated to the patients who have known hypersensitivity to this drug and in case of severe hepatic impairment.

Acute Overdose

Children: Experience in children is limited and the use of Rexant in this patient group is not recommended.

Elderly: Renal clearance in the elderly may in some cases be significantly decreased. Caution is therefore indicated when using in elderly patients.

Storage Condition

Store in a cool & dry place, protected from light & moisture. Do not freeze. Keep all medicines out of the reach of children.

Innovators Monograph

You find simplified version here Rexant

Rexant contains Tizanidine see full prescribing information from innovator Rexant Monograph, Rexant MSDS, Rexant FDA label

FAQ

What is Rexant used for?

Rexant is a short-acting muscle relaxer. It works by blocking nerve impulses (pain sensations) that are sent to your brain. Rexant is used to treat spasticity by temporarily relaxing muscle tone.Rexant may also be used for purposes not listed in this medication guide.

How safe is Rexant?

You should take Rexant only for daily activities that require relief from muscle spasms. Do not take more than three doses in a 24-hour period. Too much of this medicine can damage your liver. You will need frequent blood tests to check your liver function.

What are the common side effects of Rexant?

Rexant may cause common side effects are include:

  • dizziness
  • drowsiness
  • weakness
  • nervousness
  • depression
  • vomiting
  • tingling sensation in the arms, legs, hands, and feet
  • dry mouth
  • constipation
  • diarrhea
  • stomach pain
  • heartburn
  • increased muscle spasms
  • back pain
  • rash
  • sweating

Is Rexant safe during pregnancy?

Rexant is a category C pregnancy drug. That means two things one of these,
research in animals has shown adverse effects to the fetus when the mother takes the drug.Other are there haven’t been enough studies done in humans to be certain how the drug might affect the fetus.This drug should only be used if the potential benefit justifies the potential risk to the fetus.

Is Rexant safe during breastfeeding?

It's not known if Rexant passes into breast milk and causes side effects in a child who is breastfed. Talk with your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

Can I drink alcohol with Rexant?

Some people, especially the elderly, may also experience impairment in thinking, judgment, and motor coordination. You should avoid or limit the use of alcohol during treatment

Can I drive after takin Rexant?

It's not a good idea to drive while taking Rexant, at least until your body adjusts to the medicine. This drug can make you drowsy, which means that you should not drive a car or operate any kind of machinery that requires you to be fully alert and coordinated.

Does Rexant make me sleepy?

Rexant oral tablet may cause drowsiness. It may also cause other side effects.

How long does it take for Rexant to kick in?

Rexant is a short-acting medication, and its effects will be most noticeable between 1 and 3 hours after you take it. You should take Rexant only for daily activities that require relief from muscle spasms.

Is it safe to take Rexant every night?

You can take Rexant every six to eight hours, but you shouldn't take more than three doses in 24 hours.

Can Rexant affect my heart?

Rexant can cause changes to the normal rhythm of the heart, including an irregular heartbeat called QT prolongation. QT prolongation is a serious life-threatening condition that can cause fainting, seizures, and sudden death.

How long does it take for muscle relaxers to work?

Some muscle relaxers start working within 30 minutes of taking them, and the effects can last anywhere from 4 to 6 hours.

What does Rexant feel like?

Rexant can make you feel sleepy or dizzy. It can slow your reactions, so please take care if you are using tools or machines, or if you drive.

What does Rexant feel like?

Rexant can make you feel sleepy or dizzy. It can slow your reactions, so please take care if you are using tools or machines, or if you drive.

What does Rexant feel like?

Rexant can make you feel sleepy or dizzy. It can slow your reactions, so please take care if you are using tools or machines, or if you drive.

Is Rexant an anti inflammatory?

Rexant increases the anti-inflammatory and anti-nociceptive effects of naproxen or ketorolac, with an increase in gastric tolerability, Rexant could provide therapeutic advantages in the clinical treatment of inflammation and pain.

Can Rexant cause depression?

Rexant may cause anxiety or depression.

When should not used to Rexant?

Do not use Rexant at a time when you need muscle tone for safe balance and movement during certain activities.

How should I take Rexant?

Rexant is usually taken up to 3 times in one day. Allow 6 to 8 hours to pass between doses. Do not take more than three doses in a 24-hour period.You may take Rexant with or without food, but take it the same way each time.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Overdose symptoms may include weakness, drowsiness, confusion, slow heart rate, shallow breathing, feeling light-headed, or fainting.

What happen If I suddenly stop Rexant?

If you stop using Rexant suddenly after long-term use, you may have withdrawal symptoms such as dizziness, fast heartbeats, tremors, and anxiety.

*** Taking medicines without doctor's advice can cause long-term problems.
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