Terix

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

Terix is an allylamine with a range of antifungal activity. It is fungicidal against dermatophytes, moulds and certain dimorphic fungi. Terix is either fungicidal or fungistatic against yeasts, depending on the species. Terix interferes with fungal ergosterol biosynthesis by inhibiting squalene epoxidase in the fungal cell membrane at an early stage. This leads to a deficiency in ergosterol and to intracellular accumulation of squalene, resulting in fungal cell death. Terix is highly effective in fungal infections of the skin, hair and nails caused by Trichophyton spp., Microsporum spp. and Epidermophyton floccosum. It is also effective against yeast infections of the skin, principally those caused by the genus candida. Topical terbinafine appears to be effective in pityriasis versicolor due to Pityrosporum arbiculare.

Terix is an allylamine antifungal that inhibits squalene epoxidase (also known as squalene monooxygenase) to prevent the formation of ergosterol and cause an accumulation of squalene, weakening the cell wall of fungal cells. Terix distributes into tissues and has a long terminal elimination half life, so the duration of action is long. Overdose with terbinafine is rare, even above the therapeutic dose, so the therapeutic index is wide. Patients taking oral terbinafine should have liver function tests performed prior to treatment to reduce the risk of liver injury.

Trade Name Terix
Availability Prescription only
Generic Terbinafine
Terbinafine Other Names Terbinafina, Terbinafine, Terbinafinum
Related Drugs nystatin topical, clotrimazole topical, ketoconazole topical, itraconazole, miconazole topical, Lamisil, Lotrisone, ciclopirox topical, griseofulvin, Jublia
Weight 125mg
Type Tablet
Formula C21H25N
Weight Average: 291.4299
Monoisotopic: 291.198699805
Protein binding

Terbinafine is >99% bound to proteins in plasma, mostly to serum albumin, high and low density lipoproteins, and alpha-1-acid glycoprotein to a lesser extent.

Groups Approved, Investigational, Vet approved
Therapeutic Class Drugs for subcutaneous and systemic mycoses, Topical Antifungal preparations
Manufacturer Wns Field Pharmaceuticals
Available Country Pakistan
Last Updated: September 19, 2023 at 7:00 am
Terix
Terix

Uses

Terix cream is used for the treatment of the following dermatological infections: interdigital tinea pedis (Athlete’s foot), tinea cruris (jock itch) or tinea corporis (ring worm) due to susceptible organisms and planter tinea pedis (mocasin type) due to Trichophyton spp.

Terix tablet is used for the treatment of onychomycosis of the toe nail or finger nail due to dermatophytes and also by non-dermatophyte fungi.

Terix is also used to associated treatment for these conditions: Onychomycosis, Pityriasis versicolor, Sporotrichosis, Tinea Capitis, Tinea Corporis, Tinea Cruris, Tinea Pedis, Cutaneous candidiasis, Severe Tinea Corporis, Severe Tinea Cruris, Severe Tinea Pedis

How Terix works

Terix inhibits the enzyme squalene monooxygenase (also called squalene epoxidase), preventing the conversion of squalene to 2,3-oxydosqualene, a step in the synthesis of ergosterol. This inhibition leads to decreased ergosterol, which would normally be incorporated into the cell wall, and accumulation of squalene.

Generation of a large number of squalene containing vesicles in the cytoplasm may leach other lipids away from, and further weaken, the cell wall.

Dosage

Terix dosage

Topical application:

Terix cream to affected areas once or twice daily for 1-2 weeks may be adequate for fungal infections of the skin but certain infections may require oral Terix tablet therapy.Usual duration of treatment of Terix cream:

  • In Tinea corporis and Tinea cruris: 1-2 weeks.
  • In Tinea pedis: 2-4 weeks (One week of treatment will normally suffice if the cream is applied twice daily.).
  • In Cutaneous candidiasis: 1-2 weeks
  • In Pityriasis (tinea) versicolor: 2 weeks.

To prevent relapses in fungal infection, treatment should be continued for a adequate length of time. To apply Terix cream clean and dry the affected areas thoroughly and apply the cream once or twice a day to the affected skin and surrounding area in a thin layer and rub in lightly. In the case of intertriginous infections the application may be covered with a gauze strip, especially at night.

Oral administration:

Terix tablet is essential for hair or nail infections:

  • The usual oral dose: Terix 250 mg daily for 2 to 12 weeks depending upon the infection.
  • Finger nail onychomycosis: Terix 250 mg once daily for 6 weeks.
  • Toe nail onychomycosis: Terix 250 mg once daily for 12 weeks.

Side Effects

Terix Tablet: Abdominal discomfort, anorexia, nausea, diarrhoea, headache, rash and urticaria occasionally with arthralgia or myalgia. Less frequently taste disturbance. Rarely liver toxicity, photosensitivity, serious skin reactions etc.

Terix Cream: Redness, itching, or stinging; rarely allergic reactions.

Toxicity

The subcutaneous LD50 in rats and mice is >2g/kg. The TDLO for women is 210mg/kg/6W.

Overdose data with terbinafine is rare, however symptoms are expected to be nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache. Treat overdose with activated charcoal as well as symptomatic and supportive therapy.

Precaution

Terbifine cream is for external use only. Contact with eyes should be avoided.Good general hygiene is necessary in conjunction with the use of Terix in order to prevent reinfection (eg. from underwear, socks,shoes etc).

Terix tablet is not recommended for patients with chronic or active liver disease. Before prescribing terbinafine, pre-existing liver disease should be assessed. Hepatotoxicity may occur in patients with and without pre-existing liver disease. Pretreatment serum transaminase (ALT and AST) tests are advised for all patients before taking terbinafine tablets.

Interaction

In vivo studies have shown that terbinafine is an inhibitor of the CYP450 2D6 isozyme. Drugs predominantly metabolized by the CYP450 2D6 isozyme include the following drug classes: tricyclic antidepressants, selective serotonin reuptake inhibitors, beta-blockers, antiarrhythmics class 1C (e.g., flecainide and propafenone) and monoamine oxidase inhibitors Type B. Co-administration of terbinafine should be done with careful monitoring and may require a reduction in dose of the 2D6-metabolized drug.

Food Interaction

  • Limit caffeine intake. Terix may reduce the metabolism of caffeine by approximately 19%, monitor for increased effects of caffeine.
  • Take with or without food.

Volume of Distribution

A single 250mg oral dose of terbinafine has a volume of distribution at steady state of 947.5L or 16.6L/kg.

Elimination Route

Oral terbinafine is >70% absorbed but only 40% bioavailable after first pass metabolism, reaching a Cmax of 1µg/mL with a Tmax of 2 hours an an AUC of 4.56µg*h/mL. Over the course of a week, 1% topical terbinafine's Cmax increases from 949-1049ng/cm2

Half Life

Oral terbinafine has an effective half life of approximately 36 hours. However, the terminal half life ranges from 200-400 hours as it distributes into skin and adipose tissue. 1% topical terbinafine's half life increases over the first seven days from approximately 10-40 hours.

Clearance

A single 250mg oral dose of terbinafine has a clearance of 76L/h or 1.11L/h/kg.

Elimination Route

Terix is approximately 80% eliminated in urine, while the remainder is eliminated in feces. The unmetabolized parent drug is not present in urine.

Pregnancy & Breastfeeding use

Terix tablet: There are no adequate and well controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, and because treatment of onychomycosis can be postponed until after pregnancy is completed, it is recommended that terbinafine not be initiated during pregnancy. After oral administration, terbinafine is present in breast milk of nursing mothers. Treatment with terbinafine in not recommended in nursing mothers.

Terix cream: Foetal toxicity and fertility studies in animals suggest no adverse effects. There is no clinical experience with terbinafine in pregnant women; therefore, unless the potential benefits outweigh any potential risk, terbinafine should not be administered. Terix is excreted in breast milk and therefore mothers should not receive terbinafine treatment whilst breast-feeding.

Contraindication

Hypersensitivity to Terix or any of the excipients in thepreparation

Special Warning

Use in Children: Terix cream appears to be an effective and well-tolerated treatmenr of tinea corposis and tinea cruris in children.

Use in Elderly: Terix appears to be safe in the elderly. The dose should be reduced by half if significant hepatic or renal impairment is present.

Acute Overdose

Clinical experience regarding overdose with terbinafine tablets is limited. Doses up to 5 grams (20 times the therapeutic daily dose) have been taken without inducing serious adverse reactions. The symptoms of overdose included nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache.

Storage Condition

Store in a cool and dry place, protected from light.

Innovators Monograph

You find simplified version here Terix

Terix contains Terbinafine see full prescribing information from innovator Terix Monograph, Terix MSDS, Terix FDA label

FAQ

What is Terix prescribed for?

Terix are used to treat fungal infections of the toenails and fingernails. Terix is in a class of medications called antifungals.

How safe is Terix?

As with most classes of drugs, Terix can potentially lead to liver problems.however Terix is safer than perhaps it is perceived, and minor side effects are far more likely for most patients than serious liver damage.

What are the side effects of Terix?

Common side effects are include:

  • rash.
  • headache.
  • diarrhoea.
  • feeling or being sick (nausea or vomiting)
  • a smaller appetite than usual.
  • stomach ache.
  • indigestion.
  • muscle or joint pain

How fast does Terix work?

Terix work within 1 week after starting therapy and persist for at least 30 weeks after the completion of treatment.

Is Terix safe during pregnancy?

Terix can be used relatively safely in both oral and topical formulations during pregnancy.

Can I take Terix during breastfeeding?

Terix tablets are generally not recommended if you're breastfeeding. There are other antifungal medicines that are safer. Your doctor will recommend the best medicine for you.

Can I drink alcohol with Terix?

Yes, you can drink alcohol while using or taking Terix.

Can I drive after taking Terix?

Some people have reported feeling dizzy or giddy while they are taking Terix. If you feel like this, you should not drive or operate machinery.

What is the best time of day to take Terix?

Take Terix tablets at the same time each day, either in the morning OR in the evening.

What is the best time of day to take Terix?

Take Terix tablets at the same time each day, either in the morning or in the evening.You can take Terix with or without food.

Does Terix affect the heart?

Terix can affect your blood cells and your liver. You may need blood tests before you start and while you are taking Terix to check your blood cells and see how well your liver is working.

What happen If I missed Terix?

If you forget to take your dose, take it as soon as you remember that day. If it's nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Do not take 2 doses at the same time.

Will Terix affect my fertility?

No effect of Terix on fertility has been seen in animal studies and there are no data to suggest an effect on fertility in humans.

How long does Terix stay in my system after stop taking Terix ?

A terminal half-life of 200-400 hours may represent the slow elimination of Terix from tissues such as skin and adipose.

What should I avoid while taking Terix?

Avoid coffee, tea, cola, energy drinks or other sources of caffeine while taking Terix.

What happens when I stop taking Terix?

If you stop taking Terix too soon, your symptoms may return. Terix works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses.

Does hair grow back after Terix?

Hair will grow back by itself once a person stops taking Terix.

Is Terix bad for my liver?

Some people taking Terix have developed severe liver damage leading to liver transplant or death.

How fast does Terix work?

Terix is rapidly absorbed and widely distributed to body tissues including the poorly perfused nail matrix.

How long do side effects from Terix last?

Terix may resolve within several weeks after discontinuation of treatment, but may be prolonged,or may be permanent.

Does Terix affect periods?

You may have problems, such as bleeding between periods, while you are taking Terix . You may need to take different amounts of your medicines or you may need to take different medicines.

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