Pharm Flashcards
(33 cards)
Name a l dopa
Levo-dopa
What is it used for
It is used for Parkinson’s disease, parkinsonism
I mechan ism of action
A precusor of dopamine. works by increasing dopamine which is inhibited in the pathway between the the substanca nigra in the midbrain and the corpus stratum in the basal ganglia by acting on d2 receptors
Cannot cross bbb so given with a decarboxylase inhibitor to prevent conversion before crossing.
Side effects
Hypotension Nausea Drowsiness Hallucinations Confusion
Contraindications
Hypotension
Elderly
cvd disease
Those with psychotic disorders and on anti psychotics
Interactions
Anti emetics
Anti psychotics
Since they also act on d2 receptors
What is phenytoin used for
Seizures or status epileticus
Moa
Works by binding onto the na channel receptor to prevent na influx. This prevents action potential formation so reduces neuronal excitability
Side effects
Rash Gum hypertrophy Acne Hirutism Skin coarsening Osteomalacia Haematological disorders
What can occur in toxicity
Resp depression
Cv collapse
Contraindicated
Hepatic impairment and pregnancy since or can cause foetal hydnoin syndrome and craniofacial malformations
Interactions
It is an enzyme inhibitor so reduces effiaicu of drugs whhich are metabolised by p450 these include oestrogen progesterone and warfarin
What drugs can reduce efficacy of phenytoin and causes more adverse Side effects
Ssri and tca
enzyme inducers such as amidarone
Diltazem
Fulconazole
Name a drug that is used as a first line for trigeminal neuralgia
Carbamazepine
What else is it used for
Epilepsy
Bipolar
What does it do
Control pain reduces frequency and severity
It works by inhibiting na channels to reduce na influx and prevent action potential generation and therefore neuronal excitability
Side effects
Nausea and vomiting Ataxia and dizziness Hypersensitivity reaction including macopapular rash Oedema Hyponatraemia Anti epileptic hypersensitivity syndrome occurs in 1 in 5000 people on it or phenytoin it presents with Steven Johnson syndrome or toxic epidermal necrolysis Fever Lymphadenopathy
Contraindications
Heart renal and kidney disease should use reduced doses or with caution
In pregnancy should be referred to specialise and given high dose of folic acid or an alternative since it’s associated with neural tube defects and cleft palate
Interactions
Reduced efficacy of other drugs metabolised by cytochrome p450 since it is an enzyme inducer. Reduced efficacy of warfarin oestrogen and progesterone
It is also metabolised by this enzyme itself so it’s adverse effects can be increased with inhibitors such as macrolides
Ssri and tca which reduce seizure threshold can also reduce efficacy of other anti epileptic drugs
what can sodium valoprate be used for?
it can be used for epilepsy and it can also be used for bipolar (acute management and propylaxis)
moa
similar to previous
acts on Na channels to prevent threshold for actional potential thus reducing neuronal excitability
can also increase GABA
SE
GI irritation nausea vomiting ataxia tremors anti-epileptic hypersensitivity syndrome thrombocytopenia pancreatitis bone marrow suppression
contraindicated
child bearing age females- esp at time of conception as first trimester at high risk of foetal abnormalities and developmental delay
hepatic impairment
interactions
valproate is an enzme inhibitors of -450 therefore this can increase conc of drugs metabolised by p450 since its ability to do so is impaired. this includes warfarin, progesterone and oestrogen
additionally, its efficacy itself can be reduced by cp450 inducers such as carampazepine and carbapenems
adverse events may be increased by macrolides PPI and aspirin
antiepileptic drugs are also reduced in effiaicy by drugs that reduce seizure threshold such as TCA, SSRI Tramadol
