GPhC Exam: The Central Nervous System

GPhC Pre-Reg Exam Preparation Specialists

What are the key topics in the central nervous system?

The central nervous system is one of four high-rated therapeutic areas in the GPhC exam which covers a wide range of topics. Some of the main subsections are: hypnotics and sedatives (i.e. Midazolam, Lorazepam), antidepressants (i.e. Clomipramine, Citalopram), antipsychotics (i.e. Haloperidol), analgesics (i.e. Fentanyl, Gabapentin), antiepileptics (i.e. Lamotrigine), and drugs used in parkinsonism (i.e. Memantine, Procyclidine).

Online Course

Techniques, Tutorials & Past Pre-Reg Exam Questions With Example Answers

Private Tuition

One to One Support With A Pre-Reg Exam Preparation Specialist. Optimise Your Preparation & Success Rate.

GPhC Exam Resources & Articles
Resources & Articles

Tips, Techniques & Insight from GPhC Specialists & Past Successful Applicants

Top tips on the central nervous system GPhC exam questions

  • Familiarising yourself to the mechanism of action of a specific drug or class of drugs would be ideal as you will begin to understand why certain side effects or signs of toxicity come about. However, this can be a little difficult at times so try to make simple notes or diagrams to overcome this.
  • There are various opioid analgesics in this section however, they are often prescribed using a stepwise approach. Pain can have various causes and origins therefore, different types of pain can be targeted by different opioids and non-opioid drug options, and you need to know the differences between them.
  • Palliative care is another related topic in this section which branches off into further matters such as, pain management, constipation, convulsions, dry mouth, nausea and vomiting, restlessness and confusion. As a result, just like many other sections, the central nervous system sections intertwines with other therapeutic areas.
  • In this section, you will come across a lot of ‘Controlled Drugs’ (CDs) therefore, prepare yourself to answer questions based on ethics and legality within this area. It may be useful to use other sources which focus on the law aspects of pharmacy practice. For example, you can focus on the different schedules of controlled drugs, prescription (i.e. private, NHS) requirements, how to make CD entries etc.
  • In reality any drug can be misused and abused however, you will find that some drugs particularly in this section are commonly abused. Think about over-the-counter sales in community pharmacies – for example, are there any sale restrictions on drugs for pain relief?
  • Pre-reg students may come across patients that are suffering from alcohol/substance dependence hence, it would be helpful to know about the combination of drugs required for alcohol withdrawal.
  • During the pre-reg year some students may never see an instalment “blue” prescription thus, will not know how to complete one. Please take some time to look into these types of scripts.
  • Ensure you understand some of the prescribing/dispensing rules and guidelines for certain drugs. For example, can you switch between different brands of Sodium Valproate for epilepsy? What is the importance of the Sodium Valproate Pregnancy Prevention Programme?
Pre-Reg Exam Services

Tailor and optimise your GPhC Exam Preparation with our 1-1 Specialists or prepare in your own time with our GPhC Pre-Reg Exam Online Course & Question Bank

Narrow therapeutic index drugs in this section


Drug action

What is it used for?


Signs of toxicity

·        Reduces pre-synaptic dopamine activity thus, inhibits excitatory neurotransmission

·        Treatment and prophylaxis of mania, bipolar disorder, recurrent depression, aggressive or self-harming behaviour

·        Avoid abrupt withdrawal

·        Cardiac disease

·        Diuretic treatment

·        Myasthenia gravis

·        Psoriasis

·        QT interval prolongation

·        Increasing gastro-intestinal disturbances

·        Visual disturbances

·        Polyuria

·        Muscle weakness, tremor, abnormal reflexes

·        Confusion, drowsiness, lack of coordination

·        Hypernatraemia


Drug action

What is it used for?


(Very) common side effects


·        Inhibits sodium channel firing (this drug is a sodium channel blocker as it binds to inactivated sodium channels)

·        Tonic-clonic seizures

·        Trigeminal neuralgia

·        Prophylaxis of bipolar disorder unresponsive to lithium

·        Acute alcohol withdrawal

·        Diabetic neuropathy

·        Cardiac disease

·        Blood, hepatic, skin disorders

·        Angle-closure glaucoma

·        Dizziness, drowsiness, headache

·        Dry mouth

·        Eosinophilia, leucopenia, thrombocytopenia

·        Fatigue

·        Gastrointestinal discomfort, nausea, vomiting

·        Hyponatraemia

·        Movement disorders

·        Oedema

·        Skin reactions

·        Vision disorders

·        Weight gain


Example questions

  1. Miss P suffers from epilepsy for which she takes sodium valproate 600mg twice daily. Use the following information to work out the clearance of the drug. Write your answer in Litres/hour.

Cpss = 3mg/L                 τ = 12hrs

F = 1                               S = 0.5

  1. Mrs K is currently at an appointment with her GP. They are discussing her treatment for short-term insomnia which she has been suffering from for a few weeks, ever since the death of her father. She has previously tried two different drugs however, they were ineffective. The GP would like to prescribe a non-benzodiazepine drug for short-term use only. From the following options, which would be the most appropriate drug to prescribe?
  • Nitrazepam
  • Zolpidem tartrate
  • Clomethiazole
  • Diazepam
  • Alprazolam

Written by Fatima Sazzad, GPhC Reg No. 2212805

GPhC Exam Online Course & Question Bank

Private Pre-Reg Exam Tuition

Shopping Cart
Scroll to Top

Intensive BMAT Course

BMAT Timetable

The BMAT Course