ANTIDEPRESSANTS #5

The second group of the commonly used antidepressant is Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs).

MOA: SNRIs bind to pre-synaptic nerve endings and prevent the reuptake of both serotonin and norepinephrine, resulting in greater concentrations of both neurotransmitters in the synaptic clefts to increase neuronal activities.

ADR:

• Nausea & Vomiting
• Insomnia
• Dizziness
• Sedation
• Constipation
• Increase in blood pressure (at high doses)
• Sexual dysfunction

EX:

• Venlafaxine hydrochloride (Efexor XR*)
• Duloxetine                            (Symbalta*)

TU:

• Depression                                                                             (Venlafaxine & Duloxetine)
• Anxiety                                                                                   (Venlafaxine)
• Socialized anxiety disorder                                                    (Venlafaxine)
• Panic disorder                                                                         (Venlafaxine)
• Diabetic neuropathy                                                               (Duloxetine)
• Moderate to severe stress urinary incontinence in women (Duloxetine)

SP:

• Pregnancy & lactation
• Avoid sudden withdrawal
• Moderate to severe renal or hepatic impairment
• History of myocardial infarction
• Close blood pressure and cholestrol serum monitoring

ANTIDEPRESSANTS #4

In this post, we would be looking further into the selective serotonin reuptake inhibitors (SSRIs) group.

MOA: SSRIs bind to the pre-synaptic nerve ending and block the reuptake of serotonin. Increasing level of serotonin in the synaptic cleft enhance neuronal activities via continuous binding of that particular neurotransmitters to post-synaptic receptors.

ADR:

• Insomnia
• Nausea
• Male sexual dysfunction
• Suicidal approaches, especially in teenagers
• Headaches
• Weight loss
• Anticholinergic effects such as dry mouth and blurry vision
• Withdrawal symptoms such as tremors and anxieties

EX:

• Citalopram            (Cipram*)
• Fluoxetine             (Prozac*) 
• Fluvoxamine          (Luvox*)
• Paroxetine              (Paxil*)
• Sertraline                (Zoloft*)

TU:

• Depression                                 (Flouxetine)
• Obsessive compulsive disorder (Fluvoxamine)
• Panic disorder
• Anxiety

SP:

• Cardiac disease
• Diabetics
• Patients with unstable epilepsy
• Hepatic and renal impairment

Antidepressants #3

Currently, there are four treatment options for treating depression. They are:

1. Pharmacotherapy, by the usage of medications known as mood enhancers or antidepressants
2. Psychotherapy
3. Electroconvulsive therapy
4. Non-pharmacological treatment

For now, I am going to focus on non-pharmacological treatments. They include,

• Psychoeducation about depression and treatment options available
• Stress reduction techniques
• Balanced nutrition
• Regular exercise

For pharmacotherapeutic treatments, they include the usage of antidepressants. There are four major classes of antidepressants.

• Selective Serotonin Reuptake Inhibitors (SSRIs)
• Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs)
• Monoamine Oxidase Inhibitors (MAOi)
• Tricyclic Antidepressants (TCAs)

These antidepressants' classes would be discussed further in the next post.

Antidepressants #2

Depression could be caused by two factors, either by situations or biological.

Situational Causes of Depression.

• Unpleasant life circumstances
• Negative thinking patterns
• Substance abuse (such as drugs)

Unpleasant situations may cause depression.

Biological Causes of Depression.

• Genetics
• Hormonal imbalances
• Neurobiological dysfunction
• Symptoms from second disorder (such as head trauma or cancer)

Genetics can cause depression as well.

In the next post, we will look further into such treatment options available for depressive patients.

Antidepressants #1

Have you ever wondered what depression is? In simple words, depression is a type of mood disorder. In order to understand depression, we should first look into the definition of mood disorders.

Mood disorders are elevated or depressed moods over a period of time that affects the ability of a person to function well. There are two common types of mood disorders, mainly:

• Major depression
• Bipolar disorder (manic depression or mania)

On the other hand, depression is a disorder characterized by few common symptoms, such as:

• Depressed mood
• Lack of energy
• Sleep disturbances
• Abnormal eating patterns
• Feeling of guilt, despair and misery
• Inability to concentrate or making decisions
• GI pain, joint pains or headaches
• Obsession with death
• Avoid being around with other people
• Lack of interest in personal appearance or sex
• Hallucinations
• Delusions

Pathophysiologic explanation on depression involves three main neurotransmitters; norepinephrine, dopamine and serotonin. This explanation is divided to two hypothesis, the monoamine hypothesis and the permissive hypothesis.

Monoamine hypothesis.

In monoamine hypothesis, depression is caused by decreased concentrations of both norepinephrine and dopamine, alongside serotonin in the central nervous system.

Permissive hypothesis.

Permissive hypothesis explains that a decrease in both serotonin and norepinephrine precipitates depression. On the other hand, decreasing serotonin and increasing norepinephrine causes mania (bipolar disorder).

In the next post, I would go on further into causes of depression.

Hypnotics and Anxiolytics: Part 7.

Hydroxyzine is a another medication used in the treatment of anxiety disorders. It belongs to antihistamines group, and possess a distinct anti-emetics activity.

MOA: Hydroxyzine competes with histamine for histamine receptors (H-1), thus blocking the effects of histamine. It produces brochodilation and relaxation of skeletal muscles.

ADR:

• Drowsiness.
• CNS depression.
• Paradoxical CNS stimulation.
• Dry mouth.
• Constipation.
• Blurry vision.
• GI disturbances.
• Tachycardia.

TU:

• Mild to severe anxiety, particularly used in drug abusers due to low tendency of habituation.

PRCTN:

• Pregnant and lactating mothers.
• Porphyric patients.
• Renal and liver impairment.

The next drug would be Zolpidem, commonly used to treat both anxiety and insomniac patients.

MOA: Zolpidem acts on the subdivision of benzodiazepines receptors in CNS. It produces hypnotic effects, accompanied by strong sedation. However, the duration of action is short.

ADR:

• Nightmares.
• Agitation.
• Headache.
• GI upset.
• Dizziness.
• Daytime drowsiness.
• Euphoria.
• Vertigo.
• Confusion.

TU:

• Treatment of mild anxiety and insomnia.

PRCTN:

• Pregnant and lactating mothers.
• Obstructive sleep apnea.
• Renal and hepatic impairment.
• Myasthenia gravis.

The last type of drug used in the treatment of anxiety disorder is Zaleplon. It is also a common medication given to patients with insomnia.

MOA: Interact with GABA sub-complex type A by binding selectively with benzodiazepine-1 receptor to produce sedative and hypnotic effects.

ADR:

• Dry mouth.
• Asthenia.
• Headaches.
• Light-headedness.
• Dizziness.
• Myalgia.
• Fever.
• Migraine. 

TU:

• Treatment of anxiety and insomniac disorders.

PRCTN:

• Pregnant and lactating mothers.
• Hypersensitivity.
• Severe hepatic impairment.

Less used medications for these anxiety disorders include chloral hydrate and ethanol. Chloral hydrate produces both sedative and hypnotic effects that lasts about 30 minutes. On the other hand, ethanol is not used today due to the toxic effects that can be percipitated.

MOA: Depress the CNS via its metabolite, trichloroethanol.

ADR:

• Gastric irritation.
• Vertigo.
• Ataxia.
• Ketonuria.
• Eosinophilia.

TU:

• Treatment of insomnia and mild anxiety.

PRCTN:

• Pregnant and lactating mothers.
• Cardiac disorder patients.
• Hepatic or renal impairment.
• Porphyric patients.
• Gastritis patients.

This marks the end of this topic. If you have any questions, feel free to ask in the comment form below and I'll get back to you as soon as I can.

Hypnotics and Anxiolytics: Part 6.

The next medication would be buspirone. Buspirone is prescribed for short management of anxiety. Commonly, buspirone is given to patients with generalized anxiety disorder.

MOA: Buspirone targets mostly serotonin receptors to exert its anxiolytic activity. However, it also shows moderate affinity for dopamine receptors. Buspirone produces minimal sedation.

ADR:

• Headaches.
• Dizziness.
• Nervousness.
• Light-headedness.
• Excitement.
• Paraesthesia.
• Sleep disturbances.
• Chest pain.
• Tinnitus.

TU:

• Mild to severe anxiety.

PRCTN:

• Pregnant and lactating mothers.
• Epileptic patients.
• Renal or hepatic impairment.

Note: Buspirone is much preferred compared to Biodiazepines among elderly patients because it does not interfere with motor functions.

Hypnotics and Anxiolytics: Part 5.

Second to benzodiazepines, lies a group of anxiolytics and hypnotics called barbiturates. Barbiturates are less likely to be used today, due to their rapid tolerance, physical dependence and withdrawal symptoms.

MOA: Barbiturates interact with GABA receptors to prolong the duration of opening of chloride ion channels, usually accompanied by hypnotics and sedative effects. In addition, barbiturates also block the excitatory glutamate receptors to decrease neural activity.

ADR:

• CNS disturbances.
• Drug hangover.
• CYP450 enzyme induction.
• Addiction.
• Potential toxicity in high doses. (treatable using aminophylline)
• Sudden withdrawal symptoms.

Examples of CNS disturbances.

• Drowsiness.
• Vertigo.
• Impaired concentration.
• Mental and physical sluggishness.

Toxicity symptoms, usually observed in high doses.

• Respiratory and cardiac arrest.
• Severe drowsiness.
• Slurry speech.
• Staggering.
• Severe confusion and weakness.
• Slowed heart beats.

Sudden withdrawal symptoms.

• Tremors.
• Anxiety.
• Weakness.
• Restlessness.
• Nausea and vomiting.
• Delirium.
• Cardiac arrest.

TU:

• As anesthetics.
• As anti-convulsants.
• Anxiety.
• Insomnia.
• Nervous tension.

PRCTN:

• Pregnant and lactating mothers.
• Kidney and liver disease.
• Diabetic patients.
• Patients with prophyrias.

EX:

Long-acting Barbiturates (1-2 days).

• Phenobarbital.

Short-acting Barbiturates (3-8 hrs).

• Amobarbital.
• Pentobarbital (also blocks the high frequency sodium channels).
• Secobarbital.

Ultra-short acting Barbiturates (20 min).

• Thiopental.

Hypnotics and Anxiolytics: Part 4.

As mentioned in the previous post, we will look forward towards the agents used in treating anxiety disorders. Thus, I will discuss about the first group of hypnotics and anxiolytics known as benzodiazepines. Benzodiazepines are widely used, safer and more effective when compared to barbiturates.

MOA: Benzodiazepines bind with BZ1 and BZ2 receptors in the CNS, where these receptors are parallel to GABA receptors.

When GABA binds to its receptors, it would stimulate the chloride ion channels to open leading to influx of chloride ions. Due to this influx, hyperpolarization is induced, resulting in the movement of post-synaptic potential away from its firing threshold. This causes neural excitability to decrease. So, what kind of role do benzodiazepines play in this matter? It's easy. Benzodiazepines, when binded to their receptors, prolong the duration of opening of chloride ion channels, in order to sustain the decrement of neural excitability.

ADR: 

• Ataxia (in high doses).
• Cognitive impairment.
• Confusion.
• Daytime anxiety.
• Early morning insomnia.
• Rapid development of tolerance.

Note: The last four adverse reactions are commonly observed with the usage of triazolam.

TU:

• Anxiety disorders.
• Sleep disorders (Flurazepam, Temazepam, Triazolam).
• Panic disorders (Alprazolam).
• Grand Mal epileptic seizures.
• Muscular disorders (SM seizures) (Diazepam)

PCTN:

• Liver disease patients.
• Narrow angle glaucoma patients.

EX:

Long acting Benzodiazepines (1-3 days).

• Clorazepate (Sanor*).
• Chlordiazepoxide (Benpine*)
• Diazepam (Diapine,Diapo*).
• Flurazepam (Dalmadorm*).
• Quazepam (Doral*).

Intermediate acting Benzodiazepines (10-20 hrs).

• Alprazolam (Alpo-alpraz,Xanax*).
• Estazolam (Prosom*).
• Lorazepam (Ativan,Lorans*).
• Temazepam (Restoril*).

Short-acting Benzodiazepines (3-8 hrs).

• Oxazepam (Serax*).
• Triazolam (Somese*).

*indicates the brand names of medications in Malaysia corresponding to their generic names.

Hypnotics and Anxiolytics: Part 3.

In this part, we will look forward to the goals of treatment proposed by hypnotics and anxiolytics agents. Such goals are:

• To reduce the duration, severity and frequency of symptoms.
• To improve overall functioning of the CNS.
• To improve the quality of life.

In the next post, I would emphasize on the medications used in treating the disorders. Most commonly used medications include:

• Benzodiazepines.
• Barbiturates.
• Zolpidem.
• Zalephon.
• Buspirone.
• Hydroxyzine.

Hypnotics and Anxiolytics: Part 2.

From the previous post, I'm sure that you have already catch a glimpse about what hypnotics and anxiolytics mean. In this post, I'm going to discuss about the types of anxiety disorders. There are three types, known as,

• Generalized anxiety disorder.
• Panic disorder.
• Socialized anxiety disorder.

Patients with generalized anxiety disorder possess additional exclusive symptoms other than the symptoms of mild and severe anxiety. Such symptoms include,

• Excessive anxiety.
• Worries that are hard to control.
• Poor concentration.
• Blank mind.
• Restlessness.
• Fatigue.
• Muscle tension.
• Sleep disorder.
• Irritability.

Generalized Anxiety Disorder

On the other hand, most panic disorder patients exhibit the following symptoms,

• Depersonalization.
• Fear of losing control (like dying or to become mad).
• Abnormal distress.

Panic Disorder

Socialized panic disorder differs from the other two in the way a particular patient is scared of being scrutinized, embarassed or humiliated by people around him or her. Some examples of feared situations are,

• Talking with strangers.
• Addressing people.
• Eating or writing in front of others.
• Speaking in public.

Additional symptoms that often accompany patients with socialized anxiety disorder are blushing and diarrhea. In the next part, we will move on to the goals of such treatments related to the discussed disorders above.

Socialized Anxiety Disorder

Hypnotics and Anxiolytics: Part 1.

First, we should know what hypnotics and anxiolytics are before proceeding deep into the subject. In short, hypnotics stand for any agents that are able to produce sedation, while anxiolytics are defined as drugs used in treating anxiety disorders. To remember this easily,

HYPNOTICS = SEDATION
ANXIOLYTICS = ANTI-ANXIETY


General definition of anxiety (mild):

"Unpleasant complex combinations of emotions including fear, uneasiness and worries."

Physical effects of anxiety:

• Heart palpitations (abnormal beatings of the heart)
• Nausea
• Chest pain
• Headache

Severe anxiety on the other hand, comply with the above symptoms, with addition of:

• Tachycardia
• Trembling
• Sweating
• Sympathetic activation

Further explanation of anxiety (pathophysiology) are based on the noradrenergic model. Now, take a look at the picture below,

I'm well aware that the picture above seems rather interesting, so focus your attention on neither the doctor nor the nurse, but the patient. He looks anxious, thus based on the noradrenergic model, what is actually happening in his autonomous nervous system (ANS) could be depicted by the diagram below,

In patients with severe anxiety, their ANS is hypersensitive to various stimuli, making them in great fear or worries. This particular reaction is modulated by two neurotransmitters, noradrenaline and serotonin. That's all for now and for the next post, I'm going to discuss more on types of anxieties and their unique characteristics.

Pharmacotherapy of The CNS, GIT, Endocrine and Skeletal Systems.

Currently, I am studying in the final semester of the pharmacy course and I would like to focus on topics related to the title. For other topics, I would share the knowledge after I have finished the current semester. So, we are going to take a look at what we are going to embark in the field of pharmacotherapy. Below, I list all the topics within this part of pharmacotherapy subject.

• Introduction to CNS pharmacology.
• Drugs acting on the CNS as well as CNS stimulants.
• Antidepressant drugs.
• Hypnotic and anxiolytics drugs.
• Antischizoprenic drugs.
• Antiepileptics.
• Overview of the GIT.
• Dyspepsia and peptic ulcer disease.
• Cathartics and purgatives.
• Emesis and antiemetics.
• Introduction to endocrine system.
• Drugs affecting on endocrine system.
• Thyroid disorders and related drugs.
• Gonadal disorders and related drugs.
• Pituitary disorders and related drugs.
• Pancreas disorders and related drugs.
• Drug therapy of bones and joints disorders.
• Analgesics.
• Antipyretics.
• Anti-inflammatory drugs.

Identity: CNS stands for the Central Nervous System.

             GIT stands for the Gastrointestinal Tract.

Pharmacotherapy Online: An Introduction.

Hi everyone and greetings to those who viewed this blog. The sole reason for this blog's opening is it has been one of my visions to share numerous information regarding medications and what I have studied in pharmacy. So, enjoy and make the most out of your learning experience.