Medication Flashcards

Question

When is Eslicarbazepine indicated in epilepsy?

Answer 1

It is a weak inhibitor and inducer of certain CYP enzymes However does not auto-induce its own metabolism, affecting its half-life after cumulative doses Has a long half life so only once daily dosing is required

Answer 2

Yes there is also a risk of anti-epileptic hypersensivity syndrome.

Answer 3

Eslicarbazepine has a similar side effect profile to that of Oxcarbazepine, however it can also cause PR interval prolongation and is C/I in second or third degree AV block. Monitoring should also include plasma-sodium concentration and discontinuation should occur if hyponatremia is present. Only available in oral tablets and suspension. Again like Oxcarbazepine is a Category 2 medication, so ideally should be maintained on the same brand taking into consideration clinical and non-clinical considerations.

Answer 4

First line add on treatment: Absent seizures including childhood absence seizures Third line: Myoclonic-atonic seizures Also licensed for myoclonic seizures

Answer 5

Formulation: Oral capsules Oral solution Brand: Emeside Epesri Ethosuximide (generic) Ethosuximide is a Category 3 medication and therefore it is usually unnecessary to be maintained on the same brand, however non-clinical factors such as patient's anxiety need to be considered.

Answer 6

GI disturbances Anxiety Sleep disturbances Behavioural Ataxia Drowsiness Rash (Steven Johnson syndrome)

Answer 7

Therapeutic monitoring is not usually required only in pregnancy and renal impairment may you wish to request plasma-drug concentrations. No specific ongoing monitoring (aside from patient self-monitoring of ADRs).

Answer 8

Encourage patient self-monitoring and self-reported side effects indicating: Skin disorders: including Steven-Johnson syndrome symptoms include ulcers of the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). Rashes are often preceded by influenza-like symptoms fever, headache, body ache (flu-like symptoms) and are most likely to occur within the first few months of treatment. Blood dyscrasias: Bruising, bleeding, sore throat - request blood count Ethosuximide is also associated with suicidal behaviour tendencies, may need to be reviewed and discontinued.

Answer 9

Has good oral absorption and undergoes liver metabolism. Not a CYP inhibitor or inducer.

Answer 10

Doesn't interact with any other AEDs - possibly Carbamazepine however this has not been well studied. No listed drug interactions in the BNF

Answer 11

Believe that they are bioequivalent

Answer 12

First line monotherapy and add on: Focal seizures Generalised tonic-clonic seizures Absent seizures (unsuccessful treatment with Sodium Valproate/Ethosuximide) Tonic or atonic Idiopathic generalised epilepsy Second line and third line treatment: Myoclonic (caution as can exacerbate) Option for other epilepsy syndromes

Answer 13

Bipolar disorder (monotherapy or add on) Neuropathic pain (unlicensed)

Answer 14

Formulations: Oral tablet Dispersible tablet Brands: Lamotrigine Lamictal Lamotrigine is a Category 2 AED and therefore ideally the patient should be maintained on the same brand based on clinical and non-clinical factors. However if the brand needs to be switched a consultation with the patient should be done first with respect to clinical judgement such as previous history and seizure frequency.

Answer 15

Dizziness Drowsiness Headaches Dry mouth Diplopia (double vision) Rash (more common when used in combination with other AEDs or rapid dose titration) Hypersensivity syndrome Suicidal thoughts Blood disorders

Answer 16

No routine recommended monitoring - either therapeutic or toxic aside from self-monitoring for ADRs.

Answer 17

Encourage patient's own self-monitoring for: Skin reactions: Warn patients and carers to see their doctor immediately if rash or signs or symptoms of hypersensitivity syndrome develop. Blood disorders: Patients and their carers should be alert for symptoms and signs suggestive of bone-marrow failure, such as anaemia, bruising, or infection. Aplastic anaemia, bone-marrow depression, and pancytopenia are not as associated.

Answer 18

The half life of Lamotrigine is altered with CYP inhibitors and inducers and the dose should be adjusted accordingly. Whilst Lamotrigine does not affect other AEDs it does auto-induce its own metabolism, again affecting its half life but is classed as a non-enzyme inducer.

Answer 19

Other drugs also causing sedation Lamotrigine potentially increases the concentration of Carbamazepine and Carbamazepine decreases the concentration of Lamotrigine. (Adjust Lamotrigine dose and monitor Carbamazepine concentration). Desmopressin, severe risk of hyponatremia CYP inhibitors and inducers alter half-life and therefore concentration of Lamotrigine

Answer 20

There is no information to suggest that the two formulations are not bioequivalent.

Answer 21

First line monotherapy in: Generalised tonic-clonic (for women of childbearing potential) Focal seizures Myoclonic seizures Idiopathic generalised seizures Second line monotherapy: Absent seizures Myoclonic seizures Idiopathic generalised seizures Other epilepsy syndromes Add on: Focal seizures Generalised tonic-clonic seizures Myoclonic seizures

Answer 22

Formulation: Oral tablet Oral solution Granules for oral solution Oral granules Solution for infusion Brand: Levetiracetam Keppra Eltam Desitrend Levetiracetam is a Category 3 medication and therefore it is usually unnecessary to be maintained on the same brand, however non-clinical factors such as patient's anxiety need to be considered.

Answer 23

Drowsiness Dizziness Anxiety GI disturbances Asthenia (lack of energy) Insomnia Behavioural abnormalities (aggression, irritability) Rash Uncommon/rare side effects: Suicidal behaviours Thrombocytopenia Leukopenia

Answer 24

No specific monitoring is required however you would monitor the plasma- drug concentration in pregnancy as they decrease during pregnancy (by up to 60% in the third trimester). During other physiological changes such as puberty, aging in addition to renal impairment to avoid toxic levels.

Answer 25

Encourage patients to report if they are experiencing any suicidal behaviours as this will prompt a medication review. Patients and carers should be cautioned on the effects on driving and performance of skilled tasks—increased risk of somnolence or other CNS side-effects

Answer 26

High oral bioavailability near to 100% Linear pharmacokinetics therefore a predictable plasma concentration Not extensively metabolised with the majority excreted through the kidney unchanged Doesn't undergo CYP metabolism - only hydrolysed Is a non-enzyme inducer

Answer 27

Other drugs causing sedation Decreases the clearance rate of MTX

Answer 28

No evidence to demonstrate that they are not.

Answer 29

Not first line for any types of seizures Second-line add on therapy in: Generalised tonic-clonic Third line add on therapy in: Focal seizures Myoclonic seizures Licensed for all types except typical absence seizures as stated. IV formulation used in Status Epilepticus

Answer 30

Formulations: Oral tablet Oral solution Solution for injection Brand: Only generic Phenobarbital Phenobarbital is Category 1 AED and therefore patient's should be maintained on a specific brand as there are clinically relevant differences between brands. Increasing the potential for adverse effects and risk of loss of seizure control.

Answer 31

Steven-Johnson syndrome Bone fracture risk and bone disorders Blood disorders Folate deficiency Drowsiness Suicidal behaviours Hepatic disorders Also associated with anti-epileptic hypersensivity syndrome

Answer 32

Therapeutic monitoring: Plasma-phenobarbital concentration for optimum response is 15–40 mg/litre (60–180 micromol/litre); however, monitoring the plasma-drug concentration is less useful than with other drugs because tolerance occurs.

Answer 33

Encourage patients to report if they are experiencing any suicidal behaviours as this will prompt a medication review. Encourage self-monitoring for: Skin disorders: including Steven-Johnson syndrome symptoms include ulcers of the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). Rashes are often preceded by influenza-like symptoms fever, headache, body ache (flu-like symptoms) and are most likely to occur within the first few months of treatment.

Answer 34

Metabolism of Phenobarbital varies in neonates and in children It is partly metabolised in the liver, some is excreted unchanged from the kidney Is able to cross the placenta barrier and is also present in breast milk Is a CYP450 inducer

Answer 35

Drugs that are CYP450 metabolised (decreasing plasma concentrations/exposure) Drugs causing sedation

Answer 36

No evidence to suggest otherwise.

Answer 37

No first line indications Third line add on therapy: Focal seizures BNF indications include tonic-clonic and focal seizures however NICE states that if myoclonic or absent seizures are present they should not be used. BNF states: use in prevention of seizures during or following neurosurgery or following severe head injury.

Answer 38

Trigeminal neuralgia (unlicensed) only initiated by a specialist

Answer 39

Formulations: Oral tablet Chewable tablet Oral capsule Oral suspension Solution for injection Brand: Phenytoin sodium Dilantin Infatabs / Suspension Epanutin Infatabs / Suspension Phenytoin is Category 1 AED and therefore patient's should be maintained on a specific brand as there are clinically relevant differences between brands. Increasing the potential for adverse effects and risk of loss of seizure control.

Answer 40

Drowsy Confused Hiruitism Gingival hyperplasia (overgrowth of gums) Cerebellar dysfunction Bone and bone marrow disorders (Haematopoietic system affected) Megaloplastic anaemia

Answer 41

Above 20mg/litre

Answer 42

Nystagmus (repetitive, involuntary movements of the eyes) Diplopia (double vision) Ataxia Confusion Hyperglycaemia Slurred speech

Answer 43

Pre-screening also required for HLA-B*1502 allele (like Carbamazepine) Therapeutic monitoring of trough drug-plasma concentration: Reference range of 10-20 mg/litre Elderly, pregnancy and when counteracting medications are used, frequency of therapeutic monitoring may be increased as well as careful interpretation of the total plasma-phenytoin concentration is necessary; it may be more appropriate to measure free plasma-phenytoin concentration. Ongoing monitoring: FBC - blood dyscrasias IV use both ECG and BP should be monitored

Answer 44

Monitor for signs of Phenytoin toxicity and signs of anti-epileptic hypersensivity syndrome. Patients or their carers should be told how to recognise signs of blood or skin disorders, and advised to seek immediate medical attention if symptoms such as fever, rash, mouth ulcers, bruising, or bleeding develop. Leucopenia that is severe, progressive, or associated with clinical symptoms requires withdrawal.

Answer 45

Phenytoin is highly protein bound (90%) Phenytoin has a non-linear pharmacokinetic profile as there is saturation of the clearance pathways at therapeutic dosages, impacting the half-life. Phenytoin is a CYP 450 inducer

Answer 46

It is not possible to predict the effect of dose increases on the plasma concentration of the drug. Small dosage increases in some patients may produce large increases in plasma-drug concentration with acute toxic side-effects. Similarly, a few missed doses or a small change in drug absorption may result in a marked change in plasma-drug concentration.

Answer 47

Drugs metabolised by CYP450 (decreasing exposure of the drugs) Drugs causing sedation Amiodarone increases the exposure of Phenytoin Carbamazepine affects the concentration of Phenytoin and Phenytoin decreases the concentration of Carbamazepine.

Answer 48

Preparations containing phenytoin sodium are not bioequivalent to those containing phenytoin base (such as Epanutin Infatabs® and Epanutin® suspension); 100 mg of phenytoin sodium is approximately equivalent in therapeutic effect to 92 mg phenytoin base. Plasma-drug concentrations are required when switching formulations as it can produce clinically significant differences.

Answer 49

Check patient's adherence to their medication, Phenytoin has a half life of 22 hours - missing a dose could have significant effects due to non-linear pharmacokinetics Check patient's albumin level as 90% of Phenytoin is highly protein bound and therefore changes in albumin level can significantly affect 'free Phenytoin level' Assess the timing of the blood sample collection as it must be ensured that the blood sample is taken at the correct time relative to last Phenytoin dose, usually trough levels are measured. Double check any recent dose changes or formulation changes due to not being bioequivalent Check if the patient has recently started taking any medication, other CYP450 inducers such as Carbamazepine, Alcohol, Barbiturates, Theophylline and Rifampin, cause increase in metabolism of Phenytoin and therefore lower plasma concentrations.

Answer 50

Carbamazepine Phenobarbital Phenytoin Primidone

Answer 51

The patient's medication should be prescribed by brand as there are clinically relevant differences between brands, which if switched without close supervision and by a specialist can increase adverse effects and result in a loss of seizure control.

Answer 52

Clobazam Clonazepam Eslicarbazapine Lamotrigine Sodium Valproate Oxacarbazepine Perampenal Rufinamide Topiramate Zonisamide

Answer 53

The need for a continued supply of a particular brand is based upon clinical judgement and consultation with the patient or carer taking into account clinical and non-clinical factors.

Answer 54

Brivaracetam Ethosuximide Gabapentin Lacosamide Levetriacetam Pregabalin Tiagabine Vigabatrin

Answer 55

Usually unnecessary to be maintained on a brand however there should be a consideration for non-clinical factors.

Answer 56

Seizure frequency Treatment history Implications of a breakthrough seizure (driving)

Answer 57

Cause of anxiety in patient Confusion Loss of adherence