4.5 Miscellaneous drugs

Summary

This educational module delves into various anti-epileptic drugs, focusing on their mechanisms of action and classifications. It covers sodium channel blockers like zonisamide, phenobarbital, and lacosamide, each with unique side effects. Potassium channel openers, NMDA and AMPA antagonists, and synaptic vascular protein inhibitors are also discussed, highlighting their specific uses and potential adverse effects. Notably, lamotrigine carries a black box warning due to suicidal tendencies, while levetiracetam is favored for its efficacy and safety in pregnant women. The module concludes with a look ahead to future discussions on epilepsy first aid and management.

Takeaways

• 💊 The module covers miscellaneous anti-epileptic drugs, which are classified based on their mechanisms of action.
• 🔬 Sodium channel blockers are a subclass of drugs, including newer drugs like zonisamide, which has multiple mechanisms including carbonic anhydrase inhibition.
• 🌟 Xenosamide is used for refractory partial seizures and can cause dose-related adverse effects like dizziness and headache.
• 🧬 Aurophinamide is a sodium channel blocker used in epilepsy syndromes, with no drug interactions due to lack of metabolism by microorganismal enzymes.
• 💧 Lacosamide has a dual mechanism of action, inhibiting sodium channels and collapsing receptor-mediated protein, used for partial seizures with dose-related side effects.
• 🔋 Potassium channel openers, like retigabine, prolong after hyperpolarization to reduce neuronal excitability, used for resistant partial seizures with unique side effects.
• 💥 NMDA antagonists, such as felbamate, block NMDA receptors and voltage-gated calcium channels, used for generalized seizures but can cause serious side effects like marrow suppression.
• 🚫 AMPA antagonists, like perampanel, are used for partial seizures and have side effects like weight gain and dizziness.
• 🧠 Levetiracetam modulates synaptic vesicle protein to balance excitatory and inhibitory neurotransmitters, used for various seizure types with fewer side effects.
• 🤰 Levetiracetam is a preferred drug in epilepsy during pregnancy due to its efficacy and safety, available in different strengths for dosage adjustment.

Q & A

What are the main groups of anti-epileptic drugs discussed in the module?

The main groups of anti-epileptic drugs discussed include sodium channel blockers, potassium channel openers, NMDA antagonists, AMPA antagonists, and synaptic vascular protein inhibitors.

What is the primary mechanism of action of the newer sodium channel blockers like solid graphene glucosamine?

Solid graphene glucosamine acts primarily by blocking voltage-dependent sodium channels, inhibiting certain types of calcium channels, and causing carbonic anhydrase inhibition.

What are the adverse effects associated with solid graphene glucosamine?

Adverse effects of solid graphene glucosamine include dizziness, headache, irritability, anorexia, metabolic acidosis, nephrolithiasis, and hypohydrosis, mainly due to its carbonic anhydrase property.

How does xenosamide differ from other sodium channel blockers in terms of metabolism?

Xenosamide is unique because it is not metabolized by any microorganismal enzymes, unlike first-line sodium channel blockers such as phenytoin or carbamazepine, which means there is no drug interaction with xenosamide.

What is the dual mechanism of action of lacosamide?

Lacosamide has a dual mechanism of action: it inhibits sodium channels and also inhibits collapsing receptor-mediated protein, which is responsible for the regulation of neurotransmitter release.

What are the side effects of gizagobin, a potassium channel opener?

Gizagobin can cause physical side effects such as visual disturbances, retinal deposits, and blue pigmentation of nails and lips.

How does felbamate differ from other drugs in its class in terms of mechanism of action?

Felbamate acts as an NMDA antagonist and also blocks voltage-gated calcium channels, which is different from other drugs in its class that may target different receptors or mechanisms.

What are the potential serious side effects of felbamate?

Felbamate has potential serious side effects including bone marrow suppression and hepatotoxicity.

What is the mechanism of action of perampanel, an AMPA antagonist?

Perampanel blocks AMPA receptors, which is different from NMDA antagonists, and it is used in treating partial seizures.

What is the unique mechanism of action of levetiracetam?

Levetiracetam modulates the effect through synaptic vascular proteins, balancing the excitatory and inhibitory neurotransmitters by binding to these proteins.

Why is levetiracetam preferred in epilepsy treatment during pregnancy?

Levetiracetam is preferred in epilepsy treatment during pregnancy due to its improved efficacy and fewer adverse effects compared to other drugs, making it a first-line drug option.

Outlines

00:00

💊 Overview of Anti-Epileptic Drugs

This paragraph introduces the final module on anti-epileptic drugs, focusing on miscellaneous drugs. It reviews previously discussed drug groups like sodium channel blockers, calcium channel blockers, and those affecting the gamma-aminobutyric acid (GABA) system. The paragraph emphasizes the classification of drugs based on their mechanisms of action, including newer sodium channel blockers, potassium channel openers, and drugs affecting glutamate receptors. It also touches on synaptic vesicle protein inhibitors. Specific drugs like zonisamide, phenomena, retigabine, and the potential side effects of these drugs are mentioned, highlighting their use as add-on treatments for various seizure types. The paragraph concludes with a note on the black box warning for one of the drugs due to its association with suicidal tendencies.

05:02

🧠 Mechanisms of Anti-Epileptic Drugs

The second paragraph delves into the mechanisms of action of various anti-epileptic drugs. It discusses the role of glutamate and its receptors, including AMPA and NMDA, in epilepsy. The paragraph describes felbamate and lamotrigine as NMDA antagonists and AMPA receptor blockers, respectively, and their uses in treating specific seizure types. It also covers the side effects associated with these drugs. The paragraph then introduces levetiracetam, a drug that modulates synaptic vesicle protein to balance excitatory and inhibitory neurotransmitters. It mentions levetiracetam's benefits, including its use in pregnancy and its availability in various strengths. The paragraph concludes by setting the stage for the next module, which will cover first aid measures for epilepsy and the management of status epilepticus.

Keywords

💡Anti-epileptic drugs

Anti-epileptic drugs are medications used primarily for treating seizures by affecting the excitability of neurons in the brain. In the video, various groups of these drugs are discussed, including sodium channel blockers, calcium channel blockers, and drugs affecting the gamma-aminobutyric acid (GABA) system. These drugs are crucial in managing epilepsy by reducing the frequency and severity of seizures.

💡Sodium channel blockers

Sodium channel blockers are a class of anti-epileptic drugs that work by inhibiting the flow of sodium ions through voltage-gated sodium channels in neurons, thus stabilizing the neuronal membrane and reducing the spread of seizure activity. The script mentions newer drugs like zonisamide, which also inhibits calcium channels and carbonic anhydrase, leading to side effects such as metabolic acidosis.

💡Potassium channel openers

Potassium channel openers are a type of anti-epileptic drug that work by prolonging the after-hyperpolarization phase of neuronal activity, which reduces neuronal excitability and helps prevent seizures. The script specifically mentions eslicarbazepine acetate (also known as retigabine) as an example of a potassium channel opener used for treating partial seizures.

💡Glutamate

Glutamate is an excitatory neurotransmitter that plays a significant role in the transmission of nerve impulses in the brain. The script discusses drugs that modulate glutamate's effects, such as NMDA antagonists and AMPA antagonists, which are used to treat epilepsy by reducing the excitatory influence of glutamate.

💡NMDA antagonists

NMDA antagonists are a group of drugs that block the N-methyl-D-aspartate (NMDA) receptor, which is a type of glutamate receptor involved in synaptic plasticity and excitatory neurotransmission. In the context of the video, felbamate is mentioned as an NMDA antagonist used to treat epilepsy, but it comes with potential side effects like marrow suppression and hepatotoxicity.

💡AMPA antagonists

AMPA antagonists are drugs that block the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, another type of glutamate receptor. These drugs are used to reduce neuronal excitability and are discussed in the video as part of the treatment for epilepsy. An example given is perampanel, which has side effects like weight gain and dizziness.

💡Synaptic vesicle protein inhibitors

Synaptic vesicle protein inhibitors are a class of anti-epileptic drugs that modulate the release of neurotransmitters by interacting with synaptic vesicle proteins. The script mentions levetiracetam as an example, which balances excitatory and inhibitory neurotransmitters by binding to synaptic vesicle protein 2A, and is used to treat various forms of epilepsy.

💡Refractory partial seizures

Refractory partial seizures are a type of seizure that does not respond to treatment with standard anti-epileptic drugs. The video discusses several drugs, including eslicarbazepine acetate and lacosamide, which are used specifically to treat these difficult-to-manage seizures.

💡Status epilepticus

Status epilepticus is a life-threatening medical condition characterized by continuous or near-continuous epileptic seizures. The video mentions that the next module will discuss the management of this emergency condition, highlighting the importance of timely and appropriate intervention in such cases.

💡First aid measures for epilepsy

First aid measures for epilepsy are crucial for the immediate care of someone experiencing a seizure. Although not detailed in the provided script, the mention of discussing first aid in the next module implies the importance of educating people on how to respond to seizures, such as ensuring the person's safety and seeking medical help.

Highlights

Introduction to the last module on anti-epileptic drugs focusing on miscellaneous drugs.

Discussion on sodium channel blockers as newer drugs in epilepsy treatment.

Mention of solid graphene glucosamine as a sodium channel blocker with multiple mechanisms of action.

Xenosamide's use for refractory partial seizures and its dose-related adverse effects.

Aurophinamide's role in epilepsy syndromes and lack of drug interactions due to its metabolism.

Lacosamite's dual mechanism of action and its use in partial seizures.

Glucosamine's black box warning due to potential suicidal tendencies.

Importance of potassium channel openers in prolonging after hyperpolarization to reduce excitability.

Gizagobin's use in treating resistant partial seizures and its side effects.

Felbamate's action as an NMDA antagonist and its use in generalized seizures.

Perampanel's mechanism of blocking AMPA receptors and its side effects.

Levetiracetam's unique mechanism of modulating synaptic vesicle protein and its broad use in epilepsy.

Levetiracetam's preference in epilepsy treatment during pregnancy and its availability in various strengths.

Conclusion of the module on anti-epileptic drugs and a preview of the next module on epilepsy first aid measures.

Transcripts

welcome students to the last module of

the anti-epileptic drugs where we will

be discussing the miscellaneous drugs we

have already discussed the different

groups of drugs like sodium channel

blockers the calcium channel blockers

and rocks affecting karma system in this

module we will be discussing

miscellaneous drugs

when it comes to the messaging

structures mainly we are going to

enumerate the drugs and we want to

discuss the few salient features of this

drugs in this module

and they are classified again into the

different

subclasses depending on mechanism of

action

and sodium channel blockers we have

already discussed the important uh the

previous drugs but uh here these are the

few newer drugs which are acting by

sodium channel blockers that is zones or

phenomena

potassium channel openers like izuka

bean or reticular bean

and the drugs which affects or reduces

the glutamine effect that is nmda

antagonists like falbermate ampa

antagonist like

and

and the last group of drugs that

synaptic vascular protein inhibitors

like levator stem or brevis

whatever is it have

so now coming to each class of drugs

again the sodium channel blockers yes

the newer drugs is solid

graphene glucosamine and i already told

each anti-epileptic drugs yes mainly it

has primarily it has one mechanism

fraction but it acts by a multiple

mechanism here the drug is mainly axed

by

these dependent sodium channels along

with that it inhibits the type of

calcium channels and it also causes

carbonic anhydrase inhibition this is an

important uh

action because it leads to a lot of

other side effects

so it causes ah it's mainly used and all

these drugs are mainly used as a

add-on drugs for the

different kinds of seizures whereas

xenosamide is mainly used for

refractory partial seizures

adverse effects yes it has a dose

related adverse effect of dizziness

headache irritability anorexia but

mainly because of its the carbonic

anhydrase property it causes metabolic

acidosis nephrolithiasis or hypo

hydrosis

so the next drug is aurophinamide it is

also a sodium channel blocker

it is mainly used in epilepsy syndrome

see when we said uh the different types

of seizures the seizures can be

manifested even in form of a syndromes

where it will be associated with the

multiple other features and graphenamide

is a one such drug which mainly acts by

inhibit you know which is mainly acts in

the one type of uh seizure syndrome that

is called as linux just down syndrome

it is not metabolized by any

microorganismal enzymes like

the first line sodium channel blockers

like phenotoid or you know

the carbon muscle

so there is no drug interaction with

this drugs

the third drop in sodium channel blocker

is lacosamat lakosamite is a peculiar

drug which has two mechanism of action

it acts by inhibiting the sodium channel

yes plus it also inhibits collapsing

receptor mediated protein which is

responsible for the regulation of the

neurotransmitter release

it is also used in partial seizures and

it

also has few of the

dose related adverse effects like

dizziness headache nausea over time

so all these

three sodium channel blockers yes they

have been being used

you know nowadays as i don't talk to

other

treatments

but one point with respect to

glucosamine is it has a black box

warning because it can produce a

suicidal tendency

so we discussed sodium channel blocker

and when we were discussing the initial

mechanism of action we said always the

seizure is due to the imbalance between

the excitatory and inhibitory

neurotransmitter

and it also depends on the

depolarization and after

hyperpolarization activity of the neuron

and we all are about for after

hyperpolarization activity of a neuron

potassium channel opening is a very

important

action so gizagobin is a one drug which

is mainly

acts by the potassium channel opener

so prolongs after hyperpolarization

thereby reducing the excitability it is

also used to treat in a partial seizures

in a resistant cases

but remember the point with respect to

the peculiar side effects of physical

being which can be uh you know your

entrance questions it leads to beauty

prolongation retinal deposits blue

pigmentation of nail and lips

so two classes of drugs we have

completed here now coming to the next

class of drugs that is a drug which

reduces the glutamine effect we all know

glutamate is an important excitatory

neurotransmitter and it mainly acts by

different types of receptor like ampa

receptor nmda receptor and

kinetic receptor or

receptor two important receptor in the

action of glutamate is amphi receptor

and nmda receptor

now coming to the felba mate salvamate

is a drug which mainly acts as a nmda

antagonist it also blocks voltage

voltage-gated calcium channel along with

blocking of nmda receptor

where do we use this drug we use it to

immediately generalize dominican

scissors or a partial seizure but

it has particular side effects again or

marrow suppression or hepatotoxicity

the next step is paraphernal or lampanil

which is

used in partial seizures

again and but the mechanism of action is

opposite to that of feldman or quite

different from that because it blocks

ampa receptor not a nmda receptor but it

also has a side effects of weight gain

dizziness and soreness

uh

i think coming to the last drug in

anti-epileptic group liver is attack it

is a one peculiar drug which has a you

know specific mechanism of action of

modulating the effect through your

synaptic vascular proteins you see here

beta excitatory synapses beta inhibitory

synapses levitosetting tries to modulate

this synaptic muscular protein and

modulates the or modifies the release of

this glutamate or a gaba binding to the

release by binding to this proteins

thereby it balances the excitatory and

inhibitory neurotransmitters

so it also has adverse effects of

dizziness and solutions again used uh

generalized from the cloning species

complex

participants see and levitation is

nowadays being uh one of the important

drug or one of the what we say

uh the first line uh drug because of its

own advantage and improve efficacy and

it is also one of the drugs preferred in

epilepsy in the pregnancy it is

available in uh the different

strengths as tablets and those can be

adjusted depending on the body weight

basis also so there we complete the

module on anti-epileptic drugs so once

we've discussed all these anti-epileptic

drugs in the next module we shall

discuss

uh what is the first aid measures for

epilepsy or how do we generally measure

different types of epilepsy sutures and

how do we

manage our

important emergency condition that is a

status