Little clinical use, except methylxanthines
Can be classified in to:
› Respiratory stimulants ( Analeptics).
› Psychomotor stimulants
› Psychomimetic drugs
MOA not clear, may excite central neurons
Short acting, high margin of safety.
Low doses selective for respiratory centre
↑ Tidal volume & rate of respiration
Post-anaesthetic resp. depression
COPD i.e. hypoxemic,hypercapnic res.fail
Apnoea in premature infants
Dose- 2-5mg/min(max 4mg/kg) slow i.v
Hypoxaemic, normocapnic resp.failureasthma
Resp.fail due to neurological & muscular
High doses: convulsions & arrhythmias
No clinical use
Used as research tools
Alkaloid, convulsant poison.
Spinal cord stimulant
MOA: Blocking the receptors for Glycine
In poisoning convulsion treated withDiazepam or clonazepam slow i.v
Blocks the Cl- ion channel of GABAA.
Plant alkaloid, GABAA antagonist.
Direct depolarization of central neurons
Provides useful animal model for testing
MOA: ↑DA conc. In synaptic cleft by
Enter N endings by active transport
Displace DA(also NE) from vesicles
Also inhibits MOA-B, ↓DA metabolism.
Pharmacological effects: (central)
↑ motor activity
Euphoria & excitement
Stereotyped & psychotic behaviour
↑ BP, inhibition of GI motility
Fatigue both physical & mental reduced.
Amphetamine psychosis on repeated
use- paranoid ideas, A & T hallucinations.
Well absorbed orally
Freely penetrates BBB
Unmetabolised drug excreted in urine
Narcolepsy: Characterised by Sleep attacks during day time
Night mares in awakening state
Methylphenedate is still used
Modafinil- devoid of abuse liability
Fenfluramine, dexfenfluramine used
earlier to treat obesity
Discouraged due to: Tolerance
Insomnia, pul.htn, abuse potential.
Sibutramine new drug used now
Blocks neuronal uptake of mainly NE &
5HT (also dopamine) at hypothalamic
site that regulates food intake.
Severe obesity with risk factors like DM.
↑in HR & BP
CI in CVS diseases, withdrawn from
Sudden deaths occurred with MDMA.
Induces heat stroke like conditionrhabdomyolysis & renal failure
Inappropriate secretion of ADH
Methylenedioxy amphetamine (love drug)
75mg- psychotomimetic effects
150 mg-LSD like effects
300mg- amphetamine like
SE: tachycardia, HTN, arrhythmias
Only caffeine if used as CNS stimulant
Oral- rapid but irregular absorption
Distributed all over the body
Met: in liver by demethylation & oxid.
Metabolites excreted in urine
Gastric irritation, N, V
Nervousness, insomnia, agitation
Muscule twitch, rigidity
↑body temp,delirium, convulsions
Tachy, extra systoles at high doses
In Analgesic mixture for headache
Apnoea in premature infants
Derived from cereal fungus ergot
Hofmann synthesized & experimented on
Act as agonist at 5HT2 receptors.
Excitation threshold of retina ↓-visual
Excitation threshold of RAS↓-hyper
Experiences may be bad or good trip.
Extract of hemp plant-C.sativa, C.indica
Bhang- paste of powdered dried
leaves, used as drink
Marijuana- dried leaves & flowering
tops, smoked in pipes or rolled as
Charas or hashish- resinous exudates
leaves & flowering tops, potent smoked
THC content more in hashish
Initial CNS stimulation later sedation.
Stimulatory phaseeuphoria, ↑talkativeness, ↑appetite
Felling of confidence, relaxation & well
Other- analgesia, antiemetic
Peripheral effects- tachy, VD, reddening
Two types CB 1& 2 receptors
CB1 in brain CB2 in periphery
Anandamide-endogenous ligand CB1.
Dronabinol, Nabilone- synt.analogues of
Use: CB1 Agonists- ↑appetite in AIDS pts.
Dronabinol-antiemetic in cancer chemo.
Rimonabant : CB1 antagonist, used for
obesity, dose-20mg OD before Breakfast
AD, multi infarct dementia
Mild cognitive impairment
MR, learning defects, ADHD in children
TIA, CVA, Stroke
Sequale of head injury
ECT, brain surgery
↑ global/regional blood flow
Direct support of neuronal metabolism
Enhancement of neurotransmission
Improvement of discrete cerebral
Main pathological features:
Marked ↓ in choline acetyltransferase &
loss of cholinergic neurons in brain.
ACEs that cross BBB are preferred.
Longer acting, reversible ACE
Palliative for mild to moderate AD
Improves memory, cognition, well being
Facilitates Ach release
Newer reversible Anti cholinesterase
Better penetration in to CNS
Better tolerated & less toxic than tacrine
Clinical results modest & temporary
Donepezil: 5mg OD orally evening ↑ max
10mg after 4 wks
Rivastigmine:1.5 mg orally BD ↑ to 3mg
BD after 2 wks
Galantamine:4mg BD orally ↑to 8mg BD
after 2 wks
Transdermal Rivastigmine patch –
applied every 24hrs
SE:diarrhoe, N, V, ↑urination
Structural analogue of Ach
↓ signs & symptoms of dementia in AD
↑ cholinergic transmission
Also have antioxidant properties, slows
progression of AD
Excitotoxicity due to enhanced
Glutamate transmission via NMDA recp.
Dose:5mg OD slowly ↑ to 10-20mg/day
Non-comp. antagonist of NMDA recp.
Better tolerated, less toxic.
High doses of vit E(1000 IU B.D)
C, A, Zn, Se, bioflavonoids or spirulina ↓
progression even in middle stage AD.