Benzax F

Uses

• * Anxiety disorder
• * Short term relief of anxiety
• * Anxiety associated with depression
• * Panic disorder, with or without agoraphobia.

Fluoxetine is used for-

• Depressive illness
• Bulimia nervosa and anorexia nervosa
• Obsessive compulsive disorders
• Pre-menstrual syndrome

Benzax F is also used to associated treatment for these conditions: Anxiety, Generalized Anxiety Disorder (GAD), Panic DisorderAlcohol Dependency, Anorexia Nervosa (AN), BMI >30 kg/m2, Bulimia Nervosa, Cataplexy, Depression, Bipolar, Major Depressive Disorder (MDD), Myoclonus, Obsessive Compulsive Disorder (OCD), Panic Disorder (With or Without Agoraphobia), Premature Ejaculation, Premenstrual Dysphoric Disorder, Treatment Resistant Depression (TRD)

How Benzax F works

Alprazolam is a triazolobenzodiazepine used to treat certain anxiety and panic disorders. Alprazolam acts on benzodiazepine receptors BNZ-1 and BNZ-2. The active metabolites 4-hydroxyalprazolam acts on these receptors with 0.20 times the potency of alprazolam and alpha-hydroxyalprazolam acts on these receptors with 0.66 times the potency.

The effect of alprazolam on BNZ-1 mediates the sedation and anti-anxiety effects of the drug while the action on BNZ-2 mediates effects on memory, coordination, muscle relaxation, and anticonvulsive activity.

Alprazolam also couple with GABA-A receptors to enhance GABA binding to its receptor. This interaction mediates inhibition of the nervous system and results in a calming effect.

The molecular mechanisms as well as the clinical effects of alprazolam have both been well demonstrated, however the means by which the molecular mechanism translates to a clinical effect is still not understood.

The monoaminergic hypothesis of depression emerged in 1965 and linked depression with dysfunction of neurotransmitters such as noradrenaline and serotonin. Indeed, low levels of serotonin have been observed in the cerebrospinal fluid of patients diagnosed with depression. As a result of this hypothesis, drugs that modulate levels of serotonin such as fluoxetine were developed.

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) and as the name suggests, it exerts it's therapeutic effect by inhibiting the presynaptic reuptake of the neurotransmitter serotonin. As a result, levels of 5-hydroxytryptamine (5-HT) are increased in various parts of the brain. Further, fluoxetine has high affinity for 5-HT transporters, weak affinity for noradrenaline transporters and no affinity for dopamine transporters indicating that it is 5-HT selective.

Fluoxetine interacts to a degree with the 5-HT_2C receptor and it has been suggested that through this mechanism, it is able to increase noradrenaline and dopamine levels in the prefrontal cortex.

Dosage

Benzax F dosage

Treatment should be initiated with a dose of 0.25 to 0.5 mg three times daily. Depending on the response, dose may

be increased at intervals of 3 to 4 days in increments of no more than 1 mg per day. The maximum dose should not

exceed 4 mg/day. Occasional patients with panic disorder may need as much as 10 mg a day to achieve a

successful response and in these cases periodic reassessment and consideration of dosage adjustment is required.

Dosage should be individualized for maximum beneficial effect with a lowest possible dose. If side-effects occur at

starting dose, dose may be lowered. When discontinuing therapy, dosage should be reduced gradually by no more

than 0.5 mg every three days.

In elderly patients or in patients with advanced liver disease, the usual starting dose is 0.25 mg, two or three times

daily and may be gradually increased if needed and tolerated. Safety and effectiveness of Alprazolam in individuals

below 18 years of age have not been established.

Alprazolam XR 1 should be administered once daily, preferably in the morning by patients who are on multiple dosage

regimen of Alprazolam 0.25/0.5 mg. The tablets should be taken intact, they should not be chewed, crushed, or broken.

Initial treatment: Recent studies suggest that 20 mg/day of Fluoxetine may be sufficient to obtain satisfactory antidepressant response. Consequently, a dose of 20 mg/day administered in the morning is recommended as the initial dose.

A dose increase may be considered after several weeks if no clinical improvement is observed. Dosage above 20 mg/day, should be administered on a bid schedule (i.e. morning and noon) and should not exceed a maximum dose of 80 mg/day. As with other antidepressants, the full antidepressant effect may be delayed until 4 weeks of treatment or longer. As with many other medications, a lower or less frequent dosage should be used in patients with renal and/or hepatic impairment.

A lower or less frequent dosage should also be considered for patients, such as elderly, with concurrent disease or on multiple medication. A recommended maximum dose for elderly patients is 60 mg per day.

Maintenance treatment: It is generally agreed among expert psychopharmacologists that acute episode of depression requires several months or longer sustained pharmacologic therapy. Fluoxetine is also used in dosage of 60 mg daily for the management of bulimia nervosa.

Side Effects

Side effects, if occur, are generally observed at the beginning of therapy and usually disappear upon continued medication. The most frequent side effects are drowsiness and light headedness. The other side effects, that may occur include depression, headache, confusion, dry mouth, constipation etc.

Gastrointestinal: Nausea, vomiting, dyspepsia, dry mouth, and diarrhoea.

Neurological: Anxiety, nervousness, insomnia/ drowsiness and fatigue.

Others: Excessive sweating, pruritus, skin rashes associated with liver, kidney and lung involvement. It has therefore been advised that Fluoxetine therapy should be discontinued in any patient who develops a skin rash.

Toxicity

Alprazolam overdose can present as sleepiness, confusion, poor coordination, slow reflexes, coma, and death. Taking alprazolam with alcohol lowers the threshold for overdose. Patients should have their respiration, pulse, and blood pressure monitored. Patients can be treated by gastric lavage and intravenous fluids.. If hypotension occurs, patients may be treated with vasopressors. In known, or suspected overdoses, patients can be given the benzodiazepine receptor antagonist flumazenil in addition to other methods of management.

Oral LD50 in rats is 331-2171mg/kg.

Alprazolam is a pregnancy category D teratogen meaning there is evidence of risk to the fetus of a mother taking alprazolam but in some cases the benefit may outweigh the risk. Children born to these mothers are also at risk of withdrawal symptoms, flaccidity, and respiratory issues.

Benzodiazepines are expressed in human breast milk and so nursing is generally not recommended in mothers taking alprazolam.

Alprazolam is not associated with carcinogenicity, mutagenicity, or impairment of fertility.

In a report that included 234 fluoxetine overdose cases, it was concluded that symptoms resulting from fluoxetine overdose were generally minor and short in duration. The most common overdose adverse effects included drowsiness, tremor, tachycardia, nausea and vomiting, and providing the patient with aggressive supportive care was the recommended intervention.

Despite this evidence, more severe adverse effects have been linked to fluoxetine ingestion although most of these reports involved co-ingestion with other substances or drugs as well as other factors. For example, there is a case report that details a patient who ingested 1400 mg of fluoxetine in a suicide attempt and as a result, experienced a generalized seizure three hours later. In a separate case, a 14 year old patient ingested 1.2 g of fluoxetine and subsequently experienced tonic/clonic seizures, symptoms consistent with serotonin syndrome, and rhabdomyolysis, although the patient did not experience sustained renal injury.

Precaution

Because Alprazolam may produce psychological and physical dependence, increment of dose or abrupt discontinuation of Alprazolam therapy should not be done without physician's advice. Duration of therapy must be determined by the physicians. Alprazolam should be administered with caution to patients with hepatic or renal disease, chronic pulmonary insufficiency or sleep apnea.

As Fluoxetine undergoes hepatic metabolism and renal excretion, it should be used with caution and in reduced doses in patients with impaired hepatic or renal function. Because of its epileptogenic effect, it should be used with caution in patients with epilepsy or a history of such disorders. Fluoxetine may alter glycaemic control and therefore caution is also warranted in diabetic subjects. Depressed patients with suicidal tendencies should be carefully supervised during treatment. Fluoxetine is not usually considered a suitable form of therapy for the depressive component of bipolar (manic depressive) illness as mania may be precipitated.

Interaction

Alprazolam produces additive CNS depressant effects when co-administered with other psychotropic medications, anticonvulsants, antihistaminics, ethanol and other drugs which themselves produce CNS depression.

May lead to serotonin syndrome with serotonergic drugs (e.g. triptans, TCAs, fentanyl, tramadol, lithium, buspirone, tryptophan). May increase risk of bleeding with aspirin, NSAIDs, warfarin and other anticoagulants. May increase plasma levels of phenytoin.

Potentially Fatal: May increase risk of serotonin syndrome with concomitant admin or within 14 days of MAOIs withdrawal. May increase the QTc prolonging effect of pimozide and thioridazine.

Volume of Distribution

Volume of distribution following oral administration is 0.8-1.3L/kg. Alprazolam crosses the blood-brain barrier.

The volume of distribution of fluoxetine and it's metabolite varies between 20 to 42 L/kg.

Elimination Route

Oral bioavailability of a standard release tablet of alprazolam is 84-91% with a time to maximum concentration of 1.8 hours. A 1mg oral dose of alprazolam leads to a maximum plasma concentration of 12-22mcg/L. Alprazolam is rapidly absorbed in the gastrointestinal tract.

Data for the area under the curve and the effect of taking alprazolam with food are not readily available.

The oral bioavailability of fluoxetine is 13

In a bioequivalence study, the Cmax of fluoxetine 20 mg for the established reference formulation was 11.754 ng/mL while the Cmax for the proposed generic formulation was 11.786 ng/ml.

Fluoxetine is very lipophilic and highly plasma protein bound, allowing the drug and it's active metabolite, norfluoxetine, to be distributed to the brain.

Half Life

11.2 hours in healthy patients. The half life is 16.3h in the elderly, 5.8-65.3h in patients with alcoholic liver disease, 9.9-40.4h in obese patients. The half life is 25% higher in Asian patients compared to Caucasians. Other studies have shown the half life to be 9-16h.

The half life of fluoxetine is significant with the elimination half-life of the parent drug averaging 1-3 days after acute administration, and 4-6 days after chronic administration. Further, the elimination half life of it's active metabolite, norfluoxetine, ranges from 4-16 days after both acute and chronic administration. The half-life of fluoxetine should be considered when switching patients from fluoxetine to another antidepressant since marked accumulation occurs after chronic use. Fluoxetine's long half-life may even be beneficial when discontinuing the drug since the risk of withdrawal is minimized.

Clearance

Oral clearance is 0.90±0.21mL/min/kg but this increases to 2.13±0.54mL/min/kg when given with CYP3A inducers. Other studies have demonstrated a clearance of 0.70-1.5mL/min/kg.

The clearance value of fluoxetine in healthy patients is reported to be 9.6 ml/min/kg.

Elimination Route

Alprazolam is mainly eliminated in the urine. A large portion of the dose is eliminated as unmetabolized alprazolam. 2

Fluoxetine is primarily eliminated in the urine.

Pregnancy & Breastfeeding use

Pregnancy: Alprazolam has been categorized in pregnancy category D; that means, it should be avoided in pregnancy.

Lactation: Like other benzodiazepines, Alprazolam is assumed to be excreted in breast milk. Therefore, nursing should not be undertaken by mothers who must use Alprazolam.

Pregnancy: In animal studies, no teratogenicity or harmful effect was found. Because animal reproductive studies are not always predictive of human responses, Fluoxetine should be used in pregnancy only if clearly needed.

Lactation: As Fluoxetine is excreted in human milk, caution should be exercised when Fluoxetine is administered to nursing women.

Contraindication

Contraindicated in patients with hypersensitivity to alprazolam or other benzodiazepines. Alprazolam is also contraindicated in patients with myasthenia gravis, acute narrow angle glaucoma, during pregnancy and also in infants.

Fluoxetine Hydrochloride is contraindicated in patients known to be hypersensitive to it.

Monoamine oxidase inhibitors: There have been reports of serious, sometimes fatal reactions (including hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs and changes of mental status that include extreme agitation progressing to delirium and coma) in patients receiving Fluoxetine in combination with monoamine oxidase inhibitors (MAOIs), and in patients who have recently discontinued Fluoxetine and are then started on MAOIs. Some cases presented with features resembling neuroleptic malignant syndrome. Therefore, Fluoxetine should not be used in combination with MAOI, or within 14 days of discontinuing therapy with MAOI. Since Fluoxetine and its major metabolites have very long elimination half-lives, at least 5 weeks should be allowed after stopping Fluoxetine and before starting MAOI.

Special Warning

Use in Children: Safety and efficacy of Alprazolam in patients under the age of 18 years has not been established.

Use in children: The use of Fluoxetine in children is not recommended as safety and efficacy have not been established.

Acute Overdose

Manifestations of Alprazolam over dosage include somnolence, confusion, impaired coordination, diminished reflexes and coma. In such cases of over dosage general supportive measures should be employed along with immediate gastric lavage.

Symptoms: Nausea, vomiting, seizure, CV dysfunction ranging from asymptomatic arrhythmias to cardiac arrest (including ventricular arrhythmias and nodal rhythm) or ECG changes indicative of QTc prolongation to cardiac arrest, pulmonary dysfunction, signs of altered CNS status ranging from excitation to coma.

Management: Symptomatic and supportive treatment. May admin activated charcoal w/ sorbitol.

Storage Condition

Alprazolam tablets should be stored in a cool and dry place, protected from light and moisture.

Store between 20-25° C. Protect from light.

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