Drug interactions- summary-

Carbamazepine/phenobarbital/ phenytoin/primidone + tiagabine -

tiagabine clearance greater in patients taking carbamazepine, phenytoin, phenobarbital
or primidone. Adjust dose

Highly protein bound drugs + tiagabine/ Tiagabine + highly protein  bound drugs-
 
tiagabine is bound to plasma protein and has potential to  interact with highly protein-bound
drugs

Valproate + tiagabine / tiagabine + valproate-
tiagbine decrease steady state concentration of valproate .

Partial seizures

Adverse reactions-

CNS -     abnormal gait   4%    asthenia  22%    ataxia  8%    depression 6%
                difficulty in concentration 12%        dizziness   26%    hostility 4%
               nervousness 12%         somnolence  18%    tremor   20%

GI -        diarrhoea   2%

GU -       urinary tract infection  4%

Musculoskeletal-   myalgia  4%

Respiratory-   pharyngitis  6%

Special senses-    amblyopia   4%

Miscellaneous-    abdominal pain  4%    accidental injury   20%    flu syndrome 8%
                              infection 18%

Hypersensitivity to the drug

Special precautions-

Seizure in patients without epilepsy- in nonepileptic  patients who develop epilepsy while
on tiagabine treatment, discontiue tiagamine  and evaluate patients for an underlying seizure
disorder

Withdrawal seizures- withdraw tiagabine gradually to minimize the potential for increased
seizure frequency

Serious rash- drug associated rash can, if extensive and serious cause irreversible morbidity
even death

Hepatic function impairment- because the clearance of tiagabine reduced in patients with liver
disease,  dose reduction may be necessary in these patients

Hazardous tasks- because of possible additive depressive effects, use caution when patients
are taking other CNS depressants in combination with tiagabine

Pregnancy- use tiagabine during pregnancy only if required

Lactation- use tiagabine in women who are breast feeding only if benefits clearly outweigh the risks

Children- safety and efficacy for use in children younger than 12 years have not been established

Indication-
Partial seizures

Dosage-                                                                                        Total daily
Week 1 -  initiate at 4mg once daily                                   4mg/day

Week 2- increase total daily dose by 4mg                        8mg/day in 2 divided doses

Week -3 - increase total daily dose by 4mg                     12mg/day in 3 divided doses

Week 4- increase total daily dose by 4mg                       16mg/day in 2 to 4 divided doses

Week 5- increase total daily dose by 4 to 8mg                20 to 24mg/ day  in 2 to 4 divided doses

Week 6- increase total daily dose by 4 to 8mg                24 to 32mg /day in 2 to 4 divided doses

Usual adult maintenance dose                                           32 to 56mg in 2 to 4 divided doses

Children- 12 to 18 years - initiate 4mg once daily . Total daily dose can be increased by 4 to 8mg
at weekly intervals . Total daily dose given in 2 to 4 times daily

Dosages above 32mg have been tolerated in a small number of adolescent patients for a relative
short duration.

1. Advice patients that tiagabine can cause dizziness, somnolence, and other symptoms
    and signs of CNS depressants

2. Because of possible additive effects advice patients to use caution while taking other
    CNS depressants in combination with tigabine

3. Advice patients to inform their doctor if they are pregnant or planning to become pregnant

4. Advice patients to inform their doctor if they are breast feeding or intend to breast feed.

5. Advice patients against carrying out any operations requiring mental alertnes or dexterity
  like operating machinery, driving vehicles etc. while on treatment with tigabine unless they have
  gained sufficient experience with the usage of the drug.

Pregnancy-
Use tiagabine during pregnancy only if required

Lactation-
Use tiagabine in women who are breast feeding only if benefits clearly outweigh the risks

Children-
Safety and efficacy for use in children younger than 12 years have not been established