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JOHAN POTGIETER

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Blog #14

18 Jun 2021, 18:47 Publicly Viewable

Some of these stimulants are often used/misused by learners and students as cognitive performance enhancers.  Do a search on the internet and compile a report on the merits/ dangers of this practice.

Merits:

The merits of the these stimulants are that the students have an increased focus for the time that they are using the medication and can thus result in better academic results for the students during the time. The effects can also result in an increased confidence of the students which can also help with overall success.

Dangers:

These stimulants has severe effects on the body, e.g. hypertension. Thus it could cause serious problems for a person taking these drugs that has an undiagnosed underlying problem that will be made worse by these stimulating effects. The drugs used also has mood-destabilizing effects, thus it could create bigger problems for persons that has certain psychological disorders, e.g. bipolar disorder, that will only be worsened by the use of these stimulants instead of the needed stabilising effects.

Blog #14

18 Jun 2021, 18:26 Publicly Viewable
  • Which different groups of hallucinogenic drugs are known?

Phenylcyclidine, LSD, psychedelics, cannabinoids and anti-cholinergic drugs.

  • Name a few typical effects of the hallucinogenic drugs and discuss the clinical profile of a patient who had taken them.

Sensory (especially visual) distortion. Psychosis is also very common as well as a lack of judgement and reckless behaviour.

Someone that has taken these drugs would normally be very sedated and will also a wrong perspective on reality. A lot of times they will

  • How is an overdose of LSD dealt with? 

Parenteral Benzodiasepines are given to protect the patient against the convulsions and it is treated symptomatically to reduce the risk of a fatal overdose.

  • How is an overdose of anticholinergic drugs dealt with?

Convulsions are treated with BD’s, psychosis are treated with haloperidol/droperidol. The overdose is mostly treated symptomatically as it doesn’t cause central nervous system suppression, the most dangerous effects are the severe hypertension and the convulsions.

BLog #13

18 Jun 2021, 17:36 Publicly Viewable

You are invited to be a speaker  at a meeting of the local Women’s Organisation. The group consists mainly of middle-aged to elderly ladies. Your topic is: “Is it dangerous to use sedatives and sleeping drugs?"

Good day ladies, today I am going to speak to you about sedative sleeping drugs and if it is dangerous to be using these drugs.

Sedative and sleeping medication are both of the same medication classification, sedative hypnotics. They both work on the central nervous system and have the same effects on the central nervous system, only the potency of the effects differs.

These medications causes a decrease in inhibitions and anxiety, they also have a calming effect on the patient. These effects are what causes repeated use of these drugs, which then in turn increases the addiction potential of these drugs. It is also important to remember that, especially with previously mentioned effects in mind, most of these drugs are extremely addictive.

Just a quick note, there are two drugs that form part of this group that are used as date rape drugs. Firstly it is Flunitrazepam, Rohypnol, that is used due to it’s fast and potent onset of amnesia. The other drug is Gamma-hydroxybutyrate or GHB as well as chloralhydrate that is found in eye drops that, if mixed with alcohol, also causes a very severe sedation effect that is used during the date rape.

Sedative-hypnotics also creates a general central nervous system inhibition, which gets even worse when combined with other central nervous system suppressants. Due to this central nervous system suppression, acute overdose of these medications are very easy as well as very dangerous. Acute overdose of these drugs causes respiratory and central nervous system suppression which then leads to death.

To ensure that these medications are safely used, it is very important that these drugs are only taken as prescribed by the doctor and that these drugs are only used for short periods at a time and not long-term chronic use.

Blog #13

18 Jun 2021, 15:48 Publicly Viewable

Prepare a short “lecture” of not longer than 5 minutes (200 words), explaining to a patient what pain is, its possible causes, why different people experience pain differently and what the generally important principles of pain management and referral involve. The videos above will also be of value to complete this assignment.

Pain is an experience of sensory and emosional discomfort that could either be chronic or acute. The cause of pain is from a specific stimulus, either (for acute pain) from the skin, bone, joints, muscle, connective tissue, organs and for chronic pain could it be caused by many conditions or damage related to the nervous system. Every person experiences pain differently, because every person has a different emotional response regarding the pain and this could then influence the sensory pain that is felt in the end. Good pain management woud be to treat the cause of pain and not to just treat the feeling of pain on its own. It is also important to keep in mind that pain medications can develop very high tolerane and also have a high addiction rate, thus it is important to start with the weakest pain medication and work up to stronger medications.

Blog #12

18 Jun 2021, 15:37 Publicly Viewable
  • Using your textbooks, draw up a classification of the drugs that are used as antidepressants.

Selective Serotonin Re-uptake Inhibitors (SSRI)

Serotonin Norepinephrine Re-uptake Inhibitors (SNRI)

Tricyclic Anti-depressants (TCA)

Serotonin Modulators (5-HT modulators)

Tetracyclic and unicyclic Anti-depressants.

Monoamine Oxidase Inhibitors (MAOI)

  • What do the existing drugs all have in common regarding their mechanisms of action?

They all result in the increase in the concentration of limbic monoamines (Serotonin, Norepinephrine and Dopamine)

  • How long does it take for the antidepressive effects of these drugs to appear? What is the reason for this?

It could anything from 14-21 days or it could be even longer. The reason for this slow onset of action is due to the already low concentrations of the monoamines in the limbic system that has to firstly be restored to normal levels, this could take a long time.

  • How do the TADs and the selective serotonin reuptake inhibitors (SSRI’s) differ in respect of:
  • Efficacy

The efficacy of these medications are similar.

  • side effects

SSRI’s have less side effects than TAD’s. TAD’s also has a higher affinity to cause anti-cholinergic effects, although SSRI’s has a higher chance of causing Serotonin Syndrome.

  • safety?

SSRI’s are safer than TAD’s as they have less side effects.

  • What is the action of mirtazapine?

Mirtazepine  blocks the inhibitory Alpha2 receptors which then has an advance in the Norepinephrine and Serotonin release from presynaptic nerves.

  • What is the action of venlafaxine?

Venlafaxine is an SNRI, thus it blocks the re-uptake of 5-HT as well as NE, although it be more potent for 5-HT. This then causes an increase in presynaptic 5-HT and NE.

  • What is the action of agomelatine?

Agomelatine is a Melatonin derivative, thus it has and agonistic effect on the Melatonin (MT) 1  and 2 receptors as well as an antagonistic effect on the 5-HT2C receptors. This agonism causes a regulation of the patient’s circadian rhythm which helps the patient sleep better and then reduce the symptoms of depression.

Blog #13

18 Jun 2021, 15:05 Publicly Viewable
  • Discuss the possible mechanisms of action of lithium.

Lithium influences the 2nd messaging systems of IP3 and DAG by decreasing the enzymes that are important in the conversion and the re-circulation of membrane phosphoinositides. The influence of IP3 and DAG also has an effects on monoamine and cholinergic neurotransmission, because IP3 and DAG are very important on these neurotransmission processes.

  • What is the therapeutic index of lithium and what is its clinical significance?

The therapeutic index for Lithium is very small, 0.5-1.5mM and also toxicity when the plasma levels exceed 2mM, this causes that it is very important that patients that are receiving Lithium treatment should go for routine bloodwork to ensure that the plasma levels are still safe and effective. They should also be educated on the signs and symptoms of Lithium toxicity, that they can identify it themselves.

  • When is lithium used as single drug and in which cases and with which type of drugs is lithium combined?

Lithium is used as mono-therapy when only the mood stabilizing effects, for Bipolar Mood Disorder, are preferred for long-term and there are no episodes of acute mania.

It would be used in combination with anti-psychotics when there are episodes of acute mania.

  • Name 3 clinically significant interactions lithium may have with other drugs. Illustrate your answer with suitable examples of drugs.

Diuretics, NSAIDs, ACE inhibitors and fluoxetine all causes an increase in Lithium plasma levels, which then increases the chance for Lithium toxicity.

Neurotoxicity can be caused when used in combination with carbamazepine, Calcium-blockers, Lorsartan, Methyldopa, Metronidazole and Phenytoin.

Lithium used in combination with Traditional Anti-psychotic drugs worsens the prevalence of EPS.

  • Name the major side effects of lithium.
  • Tremors, sedation, ataxia, aphasia
  • Muscle weakness, fatigue
  • Polidypsia, poliuria, nocturia
  • Nephrogenic diabetes insipidus (Li+ interferes with kidney’s ability to concentrate urine)
  • Thyroid enlargement
  • Leucocytosis
  • Edema
  • Weight gain
  • Acne, alopecia
  • Sexual dysfunction

  • What is the status of the use of lithium during pregnancy and lactation?

Lithium has to be used in the lowest possible dose when used during pregnancy to reduce the effects of Lithium on the baby. It is however, completely contraindicated during breastfeeding.

  • Name three other important indications for lithium.

Depression, Schizophrenia as well as Huntington’s Disease.

  • Evaluate the following case and fully motivate your recommendations:

Ms B. Polar (21 years, 60 kg) is a student and used the following medication for the past two months:

Camcolith 600mg bd. The plasma levels after two weeks were 0.8mmol/l. She sustained a muscle injury and has been using Indocid® 75mg nocte for the past 10 days. On questioning she reveals that “she had picked up a lot of weight” and is now using some of her mother’s “water pills” in the hope of losing a few of the extra kilos. However, she complains of fatigue, that she has difficulty in keeping her eyes open in class, remains thirsty and constantly feels shaky and nauseous.

The symptoms that she is experiencing are all associated with Lithium toxicity. I would recommend that she would completely stop to use the diuretics (the water-pills) as well as either reduce the dose of Indocid or replace it with a non-NSAID analgesics (Paracetamol) as both of these medications increases the Lithoum levels which causes an increase in toxicity. I would also recommend that she reduce the dosage of Camcolith she takes as the weight gain is also a symptom of Lithium toxicity. To assist her in losing the weight she has gained, I would recommend she follow a diet for weight loss, as the use of diuretics without the proper indications could have serious side effects.

Blog #11

18 Jun 2021, 13:43 Publicly Viewable
  • Name an example of each of the three phenothiazine sub-families and state how they differ from one another in terms of potency and side effects.

Aliphatic side-chain:

Chlorpromazine.

Piperidine side-chain:

Periciazine.

Piperazine side-chain:

Fluphenazine.

The Aliphatic and Piperidine compounds has a low potency, thus can little EPS effects be expected. The side effects associated with these compounds are severe sedation, strong anti-cholinergic effects, strong alphalytic effects (e.g. postural hypotension) and these medications can also cause cardiotoxicity.

The Piperazine compounds has a very high potency, thus can more EPS effects be expected with the use of these compounds. They do, however have weaker anti-chlinergic effects, weaker alphalytic effects, less sedation and also less CVS side effects.

  • Which receptors in particular are blocked by the typical antipsychotic drugs?

Serotonin 2A receptors

  • How does the mechanism of action of the atypical drugs differ from that of the typical drugs?

The atypical drugs has a stronger anatgonism of Serotonin 2A receptors than  for the Dopamine 2 receptors. Where the typical drugs only has an affinity for the Mesolimbic D2 receptors.

  • Which of the receptors blocked by the older drugs reduce the risk of extrapyramidal side effects?

Dopamine 3 receptors

  • Which of the older drugs have a high incidence of extrapyramidal side effects? What is the reason for this?

Butyrophenone derivatives (Haloperidol and Droperidol), these medications are very potent Dopamine 2 blockers.

  • Because of which receptor(s) blockade do the aliphatic group of drugs have a high incidence of autonomic side effects?

Alpha-receptors.

Blog #10

1 May 2021, 16:15 Publicly Viewable
  • Dopamenergic drugs and Anticholinergic drugs
  • It’s a mnetaffinoid potentiator of dopamine, thus increasing the release and synthesis of dopamine.
  • Inhibition of MAO-B, thus decreasing the metabolism of dopamine. This then increases the doncentration of dopamine in the brain.
  • Ergot: Bromocriptine

Non-ergot: Pramipexole and Ropinirole

  • Pramipexole – Dopamine3

Ropinirole – Dopamine2

Bromocriptine – General Dopamine agonist

  • MAO-B inhibitors, they protect the neurons in the brain from further atrophy and thus decreasing the disease progression.
  • They increase the dopamine concentration in the brain as well as help decrease the disease progression.
  • They stop the stop the metabolism of L-Dopa to 3-O-Methyldopa, thus increasing the L-Dopa available to be converted to Dopamine.
  • Istradephyline decreases the amount of “off”-periods during treatment, thus increasing the effectiveness of long-term treatment.
  • Safinamide is a MOA dualist, thus it causes an increase in dopamine activity  and a decrease in glutamate realease.

Blog #9

1 May 2021, 15:59 Publicly Viewable
  • A) Myelinated fibres as easier blocked than unmyelinated fibres.

B) Pressure/touch nerves are easier blocked than the dorsal nerves that transmit pain impulses.

  • A) Anti-arrythmic effects (Class 1)

B) Weak blocking action on skeletal muscles, has no clinical application.

  • Type of procedure that require the local anesthesia.
  • Causes the drug to become ionized, thus increasing the onset of action.
  • Prilocaine in combination with Lidocaine.

Blog #8

1 May 2021, 15:48 Publicly Viewable

Cardiovascular

CNS

Renal

Hepatic

Uterus

Halothane

Decreased BP, sensitized myocardium for arythmogenic effects of catecholamines

Stadium2 absent.

Increased cerebral bloodflow and Intracranial pressure.

-

Rare and unpredictable hepatotoxicity.

Decrease muscle contraction, causing external twisting of baby.

Enflurane

No sensitization of the myocardium.

Fast and smooth induction, can cause convulsions.

-

-

-

Isoflurane

No myocardium sensitization.

Faster induction and recovery than Halothane.

-

-

-

Desflurane

Less effects than Halothane and Enflurane.

Faster induction and recovery than Isoflurane.

Increased Cerebral bloodflow and Intracranial pressure.

-

-

-

Nitrous Oxide

None

Weak anesthetic, potent analgesia, amnesia.

-

-

-

Respiratory distress.