EBIXA 10MG TABS 28`S

EBIXA contains memantine hydrochloride, an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. In Alzheimer's disease and other dementias, excessive glutamate activity leads to overstimulation of NMDA receptors, causing neuronal calcium overload and neurodegeneration.

Memantine blocks these receptors in a voltage-dependent manner, reducing pathological excitation while preserving normal synaptic transmission.

EBIXA is indicated for the treatment of moderate to severe Alzheimer's disease. It is the only approved pharmacological treatment specifically indicated for this stage of Alzheimer's, while cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are primarily used in mild to moderate stages.

In clinical trials, memantine has demonstrated statistically significant benefits in cognitive function (MMSE, ADAS-Cog), daily living activities, global clinical status, and behavioural symptoms compared to placebo. In moderate-severe Alzheimer's, it may also be combined with a cholinesterase inhibitor for additive benefit.

To minimise side effects, memantine must be started at a low dose and gradually titrated upward over 4 weeks to the maintenance dose of 20 mg once daily.

Titration Schedule (Standard)

•       Week 1: 5 mg once daily (half a 10 mg tablet).

•       Week 2: 10 mg once daily (one 10 mg tablet).

•       Week 3: 15 mg once daily (one and a half 10 mg tablets).

•       Week 4 onwards (maintenance): 20 mg once daily (two 10 mg tablets).

Administration

•       Take once daily, at the same time each day.

•       Can be taken with or without food.

•       Tablets can be halved on the score line for titration.

•       If a dose is missed, take it as soon as remembered — do not double up the next dose.

Dose Reduction

Reduce dose to 10 mg daily in moderate renal impairment (creatinine clearance 30–49 mL/min). In severe renal impairment (CrCl 5–29 mL/min), the maximum recommended dose is 10 mg daily. Memantine is not recommended in end-stage renal disease (CrCl less than 5 mL/min).

Common Side Effects (may affect 1–10 in 100 people)

•       Dizziness.

•       Headache.

•       Constipation.

• Drowsiness/somnolence.

•       High blood pressure (hypertension).

•       Confusion.

Uncommon Side Effects

•       Fatigue.

•       Vomiting, hallucinations.

•       Abnormal gait, falls.

Rare but Serious Side Effects

•       Seizures.

•       Deep vein thrombosis (DVT) or thromboembolism.

•       Psychosis.

Side effects are generally mild and most commonly occur during dose titration, often resolving as the dose stabilises.

Renal Monitoring

Memantine is renally excreted. Assess renal function before initiating and during treatment. Dose reduction is mandatory in moderate renal impairment. Use with extreme caution in severe renal impairment.

Urinary Tract Conditions

Conditions that increase urinary pH (renal tubular acidosis, severe UTI with urea-splitting bacteria) decrease memantine renal clearance, raising plasma levels. Monitor closely and consider dose reduction in these patients.

Epilepsy

Memantine can lower the seizure threshold. Use with caution in patients with epilepsy or a history of convulsions. Anticonvulsant therapy should not be discontinued.

Cardiovascular Disease

Hypertension has been reported. Monitor blood pressure during treatment, especially in patients with pre-existing cardiovascular disease or on antihypertensive therapy.

Caregiver Role

Patients with moderate-to-severe Alzheimer's disease are unlikely to be self-managing their medication. Caregivers must be clearly instructed on the titration schedule, dose administration, and what to monitor.

•       Other NMDA antagonists (amantadine, ketamine, dextromethorphan) — combined NMDA antagonism increases risk of psychotic reactions and CNS adverse effects; avoid combination.

•       Levodopa, dopaminergic agonists, anticholinergics — memantine may enhance the effects of these agents; adjust doses if necessary.

•       Neuroleptics (antipsychotics) — combination may be necessary in patients with dementia-related psychosis but increases risk of confusion, falls, and EPS.

•       Drugs that alkalinise urine (carbonic anhydrase inhibitors, sodium bicarbonate) — raise urinary pH and reduce memantine clearance, increasing plasma levels and toxicity risk.

•       Cimetidine, ranitidine, procainamide, quinidine, quinine, nicotine — all use the same renal cation transport system as memantine; potential for pharmacokinetic interaction.

•       Cholinesterase inhibitors (donepezil, rivastigmine) — can be safely combined for additive benefit in moderate-to-severe Alzheimer's.

•       Store below 25 degrees Celsius.

•       Keep in original packaging.

•       Keep out of reach and sight of children.

•       Do not use after the expiry date on the pack.

EBIXA is a prescription-only medicine (POM) in Kenya, regulated by the Pharmacy and Poisons Board (PPB). It is typically prescribed by psychiatrists, neurologists, geriatricians, or physicians experienced in managing dementia.

Given the cognitive impairment of the patient population, clear caregiver counselling and follow-up protocols are essential when dispensing.

Diagnosis Confirmation Before Prescribing

Confirm diagnosis of moderate-to-severe Alzheimer's disease (MMSE typically 10–19 for moderate, below 10 for severe). Rule out other causes of cognitive impairment (vascular dementia, LBD, FTD) before initiating. EBIXA is not licensed for mild Alzheimer's disease (though sometimes used off-label).

Combination Therapy

Memantine can be combined safely with donepezil (Aricept). The combination has shown superior outcomes to either agent alone in moderate-to-severe Alzheimer's in randomised trials. Rivastigmine and galantamine can also be combined with memantine.

Monitoring Efficacy

Assess response using validated tools: MMSE, ADAS-Cog, or Clinician's Interview-Based Impression of Change (CIBIC-Plus). Reassess at 3 and 6 months. Response can be subtle — caregiver-reported changes in behaviour, function, and quality of life are as important as formal scores.

Discontinuation Consideration

Reassess benefit annually. Consider stopping if: the patient is in late-stage Alzheimer's with minimal functional capacity; if the caregiver reports significant deterioration unresponsive to treatment; or in a palliative care setting where medication burden should be minimised.

Will EBIXA cure or reverse Alzheimer's disease?

No — EBIXA does not cure Alzheimer's disease, nor does it reverse the damage already done. It works by protecting brain cells from ongoing damage and can help maintain cognitive function, daily activities, and behaviour for longer. It is most effective in the moderate to severe stages of Alzheimer's.

Why does the dose start low and increase slowly?

Starting at a low dose and increasing gradually over 4 weeks helps the brain adjust to the medicine and minimises side effects such as dizziness and confusion. Jumping to the full dose immediately increases the risk of these side effects.

Can the person with Alzheimer's take EBIXA and a cholinesterase inhibitor at the same time?

Yes — memantine (EBIXA) and cholinesterase inhibitors such as donepezil can be safely combined and have different mechanisms of action. Clinical evidence supports that the combination provides greater benefit than either medicine alone in moderate-to-severe Alzheimer's disease.