Zonalta 8mg Tablet 7s

Zonalta 8mg Tablet 7s (Endoxifen) is an orally administered medication primarily indicated for the acute treatment of manic or mixed episodes associated with Bipolar I Disorder. Unlike its historical association with cancer drug metabolism, Endoxifen functions in psychiatry as a novel mood stabiliser, acting as a potent inhibitor of Protein Kinase C (PKC). The PKC signalling pathway is critically involved in regulating neuronal excitability, neurotransmitter release, and the plasticity of mood-regulating circuits in the brain. Overactivity of PKC is hypothesised to drive the heightened energy, impulsivity, and abnormal mood elevation characteristic of mania. By blocking this overactive signalling cascade, the dose of Endoxifen aims to rapidly stabilise mood, reduce manic severity, and facilitate the transition into a stable state for adults experiencing acute episodes.

Zonalta 8mg Tablet 7s represents a novel approach to stabilising Bipolar I Disorder, moving beyond traditional agents like lithium or antiepileptics. Its therapeutic mechanism is rooted in the current understanding of the molecular basis of mania.

Mechanism as a PKC Inhibitor

The core of Endoxifen's psychiatric action is its potent and selective inhibition of the ubiquitous signalling enzyme, Protein Kinase C (PKC).

• PKC Overactivity in Mania: Research indicates that the PKC signalling cascade is hyperactive during manic episodes, leading to downstream effects: increased neuronal excitability, excessive neurotransmitter release (particularly dopamine and glutamate), impaired cellular resilience, and altered gene expression critical for mood regulation.Signalling Cascade Blockade: Endoxifen functions by directly binding to and inhibiting PKC. By blocking this enzyme, Endoxifen effectively dampens overactive cellular signalling in key brain regions such as the prefrontal cortex and amygdala. These regulate emotion and impulse control.
• Neurotransmitter Modulation: This inhibition helps normalise the excessive release and activity of excitatory neurotransmitters (the 'drivers' of mania), promoting cellular stability and restoring balance to mood-regulating circuits.

Dose and Context

The dosage is calibrated explicitly for its use as a mood stabiliser, providing effective PKC inhibition while maintaining an acceptable safety profile. Although Endoxifen is structurally related to Tamoxifen, its use here is distinct and operates via a different mechanism (PKC inhibition vs. Estrogen Receptor modulation). Its predictable pharmacology makes it a candidate for rapid titration and adequate symptom control in the acute care setting of a manic or mixed episode.

The Oncology Link (For Context Only)

Healthcare providers need to know that Endoxifen is structurally related to the anti-cancer drug Tamoxifen, as it is its primary active metabolite. In some clinical settings, especially for CYP2D6 poor metabolizers with ER+ breast cancer, Endoxifen is being studied or approved as a Selective Estrogen Receptor Modulator (SERM). This dual therapeutic potential, while complex, underscores the potency of the molecule but requires strict attention to the prescribed indication for the 8mg formulation.

Zonalta 8mg Tablet 7s (Endoxifen 8mg) is indicated for:

Acute Treatment of Manic or Mixed Episodes:

Used in adults experiencing acute episodes of Bipolar I Disorder, characterised by abnormally elevated, expansive, or irritable mood, and increased energy or activity.

Mood Stabilisation:

Used to bring symptomatic control during the acute phase of illness.

Endoxifen offers several therapeutic benefits, particularly due to its novel mechanism of action in mood stabilisation.

• The primary benefit is the Targeted Mechanism for Mania. By specifically inhibiting the PKC pathway, Endoxifen targets a fundamental molecular driver of mania, potentially leading to a more rapid and focused therapeutic effect than agents that primarily block ion channels.

• It offers a Novel Treatment Option. For patients who have failed to respond to, or cannot tolerate, established mood stabilisers (e.g., lithium, valproate), Endoxifen provides a new avenue for effective acute control.

• The Convenient Dosing of 8mg once daily promotes better adherence, which is crucial for managing acute and long-term psychiatric illness.

The side effect profile of Endoxifen, particularly when used acutely for Bipolar Disorder, must be monitored, primarily for effects related to its partial estrogenic activity (due to its SERM structure) and the neuropsychiatric impact.

Common Side Effects (Often manageable):

• Nausea, Vomiting, or Abdominal Pain
• Fatigue or Drowsiness
• Headache, Dizziness
• Hot Flashes (due to anti-estrogenic effects)
• Dry Mouth

Serious Side Effects (Stop use and seek urgent medical attention if you experience):

• Thromboembolic Events (Blood Clots): Increased risk of Deep Vein Thrombosis (DVT), Pulmonary Embolism (PE), or stroke. Symptoms include swelling/pain in a leg, sudden shortness of breath, or slurred speech. This is a life-threatening risk.
• Endometrial Changes: Unexplained or abnormal vaginal bleeding, spotting, or pelvic pain (due to estrogen-like effect in the uterus).
• Severe Skin Reactions: Widespread rash, blisters, or signs of a severe allergic reaction.
• Hepatotoxicity: Yellowing of the eyes or skin (jaundice), or persistent upper abdominal pain, suggesting liver problems.
• Severe Psychiatric Worsening: New or worsening suicidal ideation or profound behavioural changes.

• Dosing Schedule: Take one tablet (8mg) once daily, or as prescribed. The healthcare provider may adjust dosing based on acute symptom severity and patient response.
• Timing: Take the tablet at a consistent time each day to maintain stable plasma levels.
• Administration: Swallow the tablet whole with a glass of water. It can be taken with or without food.
• Duration of Treatment: The duration is determined by the treating psychiatrist, often continuing until the acute manic episode is fully controlled, and potentially tapering thereafter or transitioning to long-term maintenance therapy.

• Report Bleeding: Any abnormal vaginal bleeding, spotting, or pelvic pain must be reported immediately due to the estrogen-like effect on the uterus.
• Monitor for Clots: Due to the risk of blood clots, maintain mobility, especially during long periods of sitting or travel (long flights).
• Take consistently: Use at the same time every day to maintain a stable plasma level, which is vital for acute mood stabilisation.
• Avoid Pregnancy: Use two forms of reliable, non-hormonal birth control throughout therapy and for two months following discontinuation.
• Inform All Doctors: Ensure all healthcare providers, including those involved in surgery or emergency care, know you are taking this drug due to the risk of thrombosis.

• Temperature: Store Zonalta 8mg Tablet 7s tablets at controlled room temperature, typically between 20 °C and 25 °C.
• Protection: Keep the medicine in its original, child-resistant container, protected from excessive heat and moisture.
• Safety: Always store securely, out of the reach and sight of children and pets. Disposal: Return expired or unused medication to a pharmacy for safe disposal.

• Food Intake: NONE. The tablet can be taken with or without food without affecting its absorption or efficacy.
• Alcohol: CAUTION. Alcohol can increase the risk of central nervous system (CNS) side effects like dizziness and drowsiness. It also interferes with mood stability and should be avoided or severely limited during the acute treatment of Bipolar I Disorder.

1. Anticoagulants (e.g., Warfarin): SEVERE CAUTION. Co-administration can significantly increase the prothrombin time and bleeding risk. Close monitoring of INR is mandatory.
2. Other CNS Depressants (e.g., Benzodiazepines, Opioids): CAUTION. Concurrent use may potentiate CNS side effects like sedation and dizziness.
3. Drugs that Affect Platelets (e.g., NSAIDs, Aspirin): CAUTION. These agents increase the risk of bleeding. The combination should be used only under strict medical supervision.
4. CYP2D6 Inhibitors/Inducers: MINIMAL RELEVANCE. Endoxifen is the active metabolite and does not rely on CYP2D6 for its efficacy, minimising the risk of interaction seen with Tamoxifen.

• History of Thromboembolic Disease (DVT/PE): SEVERE CAUTION. Use is generally avoided or requires a strict risk-benefit assessment due to the increased risk of recurrence.
• Active Liver Disease: CAUTION. The drug is metabolised in the liver. Use with caution in patients with severe hepatic impairment.
• History of Endometrial Hyperplasia/Cancer: CONTRAINDICATED. Due to its estrogen-like (agonistic) effects in the uterus, it should not be used in patients with pre-existing severe uterine pathology.

The established dosage for acute Bipolar I treatment is Endoxifen once daily. This dose is critical for achieving and maintaining the stable plasma concentration required to sustain effective PKC inhibition and stabilise the acute manic episode.

Overdose symptoms are likely to be severe exaggerations of the primary side effects, including extreme CNS effects (confusion, agitation), severe gastrointestinal distress, and a substantially increased risk of life-threatening thromboembolic events and QTc prolongation (cardiac risk). Treatment is symptomatic and supportive. Given the severe potential for thrombosis and cardiac complications, if an overdose is suspected, seek emergency medical help immediately.

Consistent daily dosing is vital for stabilising an acute manic episode.

• Missed Dose: If you miss your scheduled dose, take it as soon as you remember.
• Near Next Dose: If it is almost time for your next scheduled dose (e.g., within 12 hours), skip the missed dose.
• Do Not Double Dose: Never take two tablets to compensate for a forgotten one, as this increases the risk of side effects, particularly thromboembolic events. Resume your regular daily schedule.
• Contact Your Doctor: If you miss multiple doses, inform your psychiatrist immediately, as this may compromise control of the acute episode.