GI Drugs

Question 1

What medications cause constipation?

Answer 1

• Opioids
• Iron
• Antipsychotics including Clozapine
• Diuretics
• Verapamil

Question 2

What are the types of laxatives?

Answer 2

Bulk forming
Osmotic laxative
Stool softeners
Stimulant
Bowel cleansing agent
Prucalopride

Question 3

Adverse effects of laxatives

Answer 3

Bulk forming : flatulence & bloating
Osmotic laxative : abdominal cramps , bloating , flatulence , nausea & vomiting
Stimulant laxative : abdominal cramps , diarrhoea, nausea & vomiting, senna may cause yellow-brown colour of urine
Prucalopride : headache, abdominal pain, nausea, diarrhoea

Question 4

Management of constipation

Answer 4

• 3 months or less
• Lifestyle advice
• Fruit & vegetables
• Fibre : gradually increase aiming for 30g a day
• Increase fluid intake
• Exercise

• Bulk forming
• Stools hard or difficult to pass – Osmotic Laxatives
• Stools soft but difficult to pass – Stimulant laxatives

Question 5

Treatment for opioid induced constipation

Answer 5

Lifestyle
NO Bulk forming laxative
Osmotic laxative plus stimulant
Gradually reduce laxative

Question 6

What medications can cause diarrhoea?

Answer 6

• Laxatives
• Antacids that have magnesium
• Antibiotics
• Chemotherapy
• Proton pump inhibitors
• Medicines that suppress the immune system (such as mycophenolate).
• Nonsteroidal anti-inflammatory drugs (NSAIDs) used to treat pain and arthritis, such as ibuprofen and naproxen.
• Metformin (if so used modified release)
• Colchicine

Question 7

Treatment of diarrhoea:

Answer 7

• Prevention of fluid & electrolyte disturbance
• Most episodes self limiting
• Oral rehydration sachets
• Severe dehydration : IV fluids

• Loperamide –
• binds to the opiate receptor in the gut wall. It inhibits the release of acetylcholine and prostaglandins, thereby reducing propulsive peristalsis, and increasing intestinal transit time.
• Loperamide increases the tone of the anal sphincter, thereby reducing incontinence and urgency.
• Overdoses QT prolongation

• Codeine used for its side effect
• Travellers diarrhoea : Ciprofloxacin
SICK Days rules : NSAIDs, ACE, Diuretics
Stop medication if at risk of dehydration

Question 8

Medications that can cause dyspepsia

Answer 8

•NSAIDs (including aspirin)
•Corticosteroids
•Calcium-channel blockers
•Nitrates
•Theophylline
•Bisphosphonates e.g. Alendronate .
•combination of selective serotonin-reuptake inhibitors and NSAIDs/aspirin significantly increases a person’s risk of GI bleeding

Question 9

Medications for dyspepsia/GORD

Answer 9

• First step
• Oral Antacids (gaviscon)
• Best given when symptoms occur or are expected
• Usually meals & at bedtime
• Acid neutralisation
• Increase viscosity of stomach contents protecting from acid reflux

Question 10

Proton pump inhibitors examples

Answer 10

Lansoprazole , Pantoprazole , Omeprazole , Esomeprazole, Rabeprazole

Question 11

H2 receptor antagonists examples

Answer 11

• Main ones : Nizatidine , Famotidine,
•Cimetidine (not recommended as there is a higher risk of drug interactions, due to inhibition of cytochrome P450 enzymes.)

Question 12

H2 receptor antagonists:

Answer 12

• Heal gastric & duodenal ulcers by reducing gastric acid output by blocking H2 receptors
• Reduce basal acid secretion & pepsin production – by 60%
• Takes longer to act
• Uses
• Symptoms of GORD
• Prophylaxis of NSAID associated gastric & peptic ulcer
• Can add along with a PPI particularly if night time symptoms
• NOT Zollinger Ellison syndrome
• Rantidine : issues!
Famotidne, Nizatidine

Question 13

H Pylori testing

Answer 13

Carbon- 13 urea breath test or a stool antigen test

Question 14

Dossing of PPI: Proven GORD

Answer 14

• If the person has proven GORD:
• Offer a full-dose proton pump inhibitor (PPI) for 4 weeks to aid healing.
• If the person has proven severe oesophagitis:
• Offer a full-dose PPI for 8 weeks to aid healing.
• Offer a full-dose PPI long-term as maintenance treatment.
• Do not arrange testing for Helicobacter pylori infection.

Question 15

Laxative samples by mechanism of action

Answer 15

1st Bulk forming
Examples
psyllium
Methylcellulose
Ispaghula (fibre gel)

2nd Osmotic
Examples
Magnesium hydroxide
Macrogol
Lactulose
Phosphate enema

3rd Stimulant
Examples
Bisacodyl
Senna
Castor oil
Sodium picosulphate

Question 16

Treatment for peptic ulcer

Answer 16

• If the person tests positive for H. pylori infection with a proven gastric or duodenal ulcer which is:
• Associated with NSAID use — prescribe full-dose PPI therapy for 2 months, then prescribe
first-line eradication therapy after completion of PPI therapy.
• Not associated with NSAID use — prescribe first-line eradication therapy.
• If the person tests negative for H. pylori infection with a proven gastric or duodenal ulcer:
• Prescribe full-dose PPI therapy for 4–8 weeks, depending on clinical judgement.

Question 17

Dyspepsia in pregnancy

Answer 17

• Lifestyle advice
• Antacids and alginates are recommended as first-line treatments if symptoms are relatively mild and are not controlled adequately by lifestyle changes.
• If symptoms are severe, or persist despite treatment with an antacid or alginate, consider prescribing an acid- suppressing drug.
• CKS recommends omeprazole.

Question 18

GI bleed treatment

Answer 18

• 10%hospitalmortalityrate
• Most common peptic ulcer or oesophagogastric varices
• IV PPI 8mg / hr – prolong acid suppression
• Current international consensus guidelines recommend high-dose i.e. PPI therapy e.g. Pantoprazole 80 mg bolus followed by 8 mg h−1 for 3 days.- reduces risk of rebleeding & need for surgery
• Critically ill – H2 / PPI oral or IV to prevent stress upper GI bleeding

Question 19

Antispasmodics examples

Answer 19

• Used as required for abdominal pain or spasm in IBS
• Mebeverine , Alverine & Peppermint oil : direct acting smooth muscle relaxant • Linaclotide : moderate to severe IBS with constipation
• Contra-indications :
• Intestinal obstruction • Paralytic ileus

Question 20

• Mr James Parsonage has been sent in from the nursing home to ED as the nursing staff noted he was very listless & has profuse diarrhoea.
• His DOB 20/10/36
• Weight 70 kg
• Allergies – amlodipine swollen ankles
• PMH – type 2 diabetes, osteoporosis, heart failure
• Recently he has suffered from a chest infection which has resolved & was treated with 5 days of co-amoxiclav 375mg TDS
• His Observations are all within normal range
• Na 144 (135-145), K 5 (3.5-5), Urea 23 (2.5-7.1) Cr 155 (88-115), FBC NAD

Answer 20

Co-amoxiclav- risk of C diff
K – at the top range of normal
Urea – increased & Cr – increased : diarrhoea leading to dehydration & acute kidney injury

Question 21

Treatment for c.Diff toxin and antigen is positive

Answer 21

• First-line antibiotic for a first episode of mild, moderate or severe C. difficile infection
• Vancomycin: 125 mg orally four times a day for 10 days

Question 22

A 73 year old lady presents to her GP with symptoms of epigastric tenderness , heartburn & bloating,& belching over a three month period. Her weight has been stable. The GP diagnoses dyspepsia & books an endoscopy
Which one of the following medications may have contributed to this patients presenting symptoms?

• Paracetamol
• Lansoprazole
• Ezetimibe
• Alendronic acid
• Vitamin B12 injections

Answer 22

• Alendronic acid

Question 23

• You are working in the gastro clinic & your next patient has been referred by his GP. He is 56 years old and has a four month history of epigastric pain and excessive postprandial fullness, also episodic bloating, He has not vomited or suffered from dysphagia.
• He uses Gaviscon prn, smokes 15 cigarettes a day and describes himself as a social drinker . You diagnose dyspepsia

Which two of the following would be acceptable options for initial management of this patient?
1. Refer for endoscopy
2. Prescribe 4 weeks of famotidine & ask the patient to see his GP is symptoms persist
3. Prescribe 4 weeks of lansoprazole and ask the patient to see their GP is symptoms persist
4. Advise the GP to arrange a H Pylori test , ask the GP to prescribe eradication therapy is positive or 4 weeks of PPI is negative & ask patient to return if symptoms persist.

Answer 23

Answer 3 and 4 based on NICE

Question 24

You give Mr P a prescription for a four week course of a standard dose PPI and advise him to take the medication 30-60 mins before breakfast and discharge him from clinic. You advise him to go back to the GP if symptoms persist after the 4 week course.
PPI therapy has recognised side effects. Which of the following are recognised side effects?
1. Diarrhoea
2. Iron deficiency anaemia
3. Increased risk of fragility fractures
4. Parietal cell hyperplasia

Answer 24

All apart from iron deficient anaemia

Question 25

• Martin is 53 and tested positive for H Pylori three months ago. He was given triple therapy as per the local guidelines but stopped the antibiotics after 3 days as they gave him diarrhoea and just continued on the PPI . His symptoms of epigastric pain & nausea persist but he has no red flag symptoms.
• How would you manage?
1. Increase his PPI & review in 6 weeks time
2. Stop the PPI for two weeks & repeat the H Pylori test
3. Continue the PPI & repeat the H Pylori test
4. Refer for routine endoscopy
5. Stop the PPI & switch to a H2 receptor antagonist

Answer 25

2. Stop the PPI for two weeks and repeat he H Pylori test

Question 26

A 25 year old female who is pregnant presents asking for something to help with her constipation. She explains she has tried to increase her fruit & veg and her fluid intake but it is not helping. What is the next treatment line?

Fybogel
Senna
Sodium Picosulphate
Macrogol
Loperamide

Answer 26

Fybogel - bulking

Question 27

• A 60 year old on morphine 30mg BD has used senna already but symptoms of constipation still remain really struggling
• What would you recommend adding?

Answer 27

Osmotic and stimulant Macrogel & sodium picosulphate/ senna

Question 28

A 29 year old female attends her OP chemo appointment ready for her next round of chemotherapy Irinotecan . Which would you recommend prescribing as she experiences diarrhoea a few hours after having chemotherapy ?

Answer 28

Dose loperamide 4mg first intake then 2mg every 2 hours

Question 29

You see and 85 year old man with constipation. He has manic depression , osteoarthritis, epilepsy and atrial fibrillation. Which of his medications are LEAST likely to be the cause of his constipation?
• Haloperidol
• Naproxen
• Iron Sulphate
• Phenytoin
• Warfarin

Answer 29

Haloperdiol – anticholinergic side effect
Naproxen – may decrease colon
Iron sulphate : can cause constipation or diarrhoea
Phenytoin : can cause diarrhoea
Warfarin : LEAST likely

Question 30

A 72 year old woman is admitted with bronchopneumonia and started on oxygen and IV amoxicillin. She previously has a bowel motion every day but she has not had a trip to the toilet by day 5 of her admission. She has tried unsuccessfully to sit on the toilet and empty her bowel she in now developing Abdo pain. She has been receiving 2 litres of IV fluids a day. Her rectum is empty on PR. What would you do next?
1. Start an osmotic laxative
2. Prescribe a suppository
3. Organise an Abdo x-ray to confirm her constipation
4. Recommend a high fibre diet

Answer 30

Start an osmotic laxative

Question 31

Antiemetics

Answer 31

u Cyclizine (histamine H1-receptor antagonist)
u Metoclopramide (D2 receptor antagonist) prokinetic (not in young
people, Parkinson’s, phaemochromocytoma)
u Ondansetron (serotonin 5-HT3 receptor antagonist)
u Domperidone (D2 receptor antagonist – doesn’t cross the blood brain barrier)
u If an anti-emetic is required in pregnancy, prescribe an antihistamine (oral cyclizine or oral promethazine), or a phenothiazine (oral prochlorperazine), and reassess after 24 hours.

Question 32

First line and second line treatment in inducing remission in Crohn’s

Answer 32

Inducing Remission
• First line: Steroids (e.g. oral prednisolone or IV hydrocortisone)

• If steroids alone don’t work, consider adding immunosuppressant medication under specialist guidance:
○ Azathioprine
○ Mercaptopurine
○ Methotrexate
○ Infliximab
○ Adalimumab

Question 33

Medication to maintain remission within Crohn’s disease

Answer 33

• First line = thiopurines:
○ Work through purine synthesis inhibition in lymphocytes -> immunosuppressive properties
○ E.g.Mercaptopurine + Azathioprine
○ SE: pancreatitis + hepatotoxicty

• Alternatives:
○ Methotrexate
▪ Inhibits dihydrofolate reductase
▪ Immunomodulatory + anti-inflammatory properties
▪ SE: bone marrow suppression, hepatotoxicity + pulmonary toxicity

○ Monoclonal antibodies
▪ E.g. Infliximab + Adalimumab
▪ SE: numbness/tingling, vision problems, leg weakness, chest pain, SOB, new joint pain, hives/itching

Question 34

What medication is used to induce remission in a UC flare up/ first diagnosis?

Answer 34

Aminosalicylates (mesalazine) (5-ASA) and/or steroids.
Firstly assess severity using True love and Witts

Moderate: Topical 5-ASA (suppository) +/- Oral 5-ASA +/- Oral Steroids -> Treat as severe if no better in 2 weeks Severe: Admit, IV Hydrocortisone, IV Fluids -> Step-down to oral when well

Steroids - 40mg pred and wean by 5mg each week.

Question 35

Maintenance therapy in ulcerative colitis

Answer 35

Pharmacological options to maintain remission in UC predominantly include thiopurines and biologics. These are considered in patients who fail to respond to remission therapy (e.g. steroid-refractory), those who have two or more flares within a 12 month period or those who are steroid-dependent.

• Thiopurines (azathioprine and mercaptopurine): work through purine synthesis inhibition in lymphocytes leading to immunosuppression. Must check TPMT enzyme activity before use. Homozygous mutations in TPMT can lead to dangerous bone marrow suppression. Major side-effects include pancreatitis and hepatotoxicity.
• Biologics: refers to monoclonal antibodies. Options include infliximab (infusion)/adalimumab (sub cut) (tumour necrosis factor alpha inhibitors), vedolizumab (alpha-4/beta-7 integrin inhibitor) and tofacitinib (JAK inhibitor). More biologic agents are being tested in clinical trials.

Question 36

IBS first line medications

Answer 36

First-line medications depend on the symptoms:
○ Loperamide for diarrhoea
○ Bulk-forming laxatives (e.g., ispaghula husk) for constipation (lactulose can cause bloating and is avoided)
Antispasmodics for cramps (e.g., mebeverine, alverine, hyoscine butylbromide or peppermint oil)

Linaclotide is a specialist secretory drug for constipation in IBS when first-line laxatives are inadequate.
Other options include where symptoms remain uncontrolled:
§ Low-dose tricyclic antidepressants (e.g., amitriptyline)
§ SSRI antidepressants
§ Cognitive behavioural therapy (CBT)
§ Specialist referral for further management

Question 37

Management of chronic pancreatitis

Answer 37

Management of Chronic Pancreatitis

Abstinence from alcohol and smoking is important in managing symptoms and complications.

Analgesia can be used to manage the pain, although it can be severe and difficult to manage.

Replacement pancreatic enzymes (Creon) may be required if there is a loss of pancreatic enzymes (i.e. lipase). Otherwise, a lack of enzymes leads to malabsorption of fat, greasy stools (steatorrhoea), and deficiency in fat-soluble vitamins.

Subcutaneous insulin regimes may be required to treat diabetes.
ERCP with stenting can be used to treat strictures and obstruction to the biliary system and pancreatic duct.

Surgery may be required by specialist centres to treat:
• Severe chronic pain (draining the ducts and removing inflamed pancreatic tissue)
• Obstruction of the biliary system and pancreatic duct
• Pseudocysts
• Abscesses

Question 38

Prophylaxis of bleeding in stable oesophageal varices

Answer 38

Prophylaxis of bleeding in stable oesophageal varices involves:
○ Non-selective beta blockers (e.g., propranolol) first-line
○ Variceal band ligation (if beta blockers are contraindicated)

	Variceal band ligation involves a rubber band wrapped around the base of the varices, cutting off the blood flow through the vessels.

Question 39

Management of ascites

Answer 39

Management options include:
• Low sodium diet
• Aldosterone antagonists (e.g., spironolactone)
• Paracentesis (ascitic tap or ascitic drain)
• Prophylactic antibiotics (ciprofloxacin or norfloxacin) when there is <15 g/litre of protein in the ascitic fluid
• Transjugular intrahepatic portosystemic shunt (TIPS) is considered in refractory ascites
• Liver transplantation is considered in refractory ascites

Question 40

Autoimmune hepatitis treatment

Answer 40

• High dose steroids (prednisolone) that are tapered over time as other immunosuppressants, particularly azathioprine, are introduced. Immunosuppressant treatment is usually successful in inducing remission however it is usually required life long.

Question 41

Management of hep B and C

Answer 41

Management of hepatitis B/C involves:
○ A low threshold for screening patients at risk of hepatitis B
○ Screen for other viral infections (e.g., HIV, hepatitis A, C and D)
○ Referral to gastroenterology, hepatology or infectious diseases for specialist management
○ Avoid alcohol
○ Education about reducing transmission
○ Contact tracing and informing potential at-risk contacts
○ Testing for complications (e.g., FibroScan for cirrhosis and ultrasound for hepatocellular carcinoma)
○ Antiviral medication can be used to slow the progression of the disease and reduce infectivity
○ Liver transplantation for liver failure (fulminant hepatitis)

Question 42

Treatment for hepatic encephalopathy

Answer 42

Management involves:
○ Lactulose (aiming for 2-3 soft stools daily)
○ Antibiotics (e.g., rifaximin) to reduce the number of intestinal bacteria producing ammonia
○ Nutritional support (nasogastric feeding may be required)

Lactulose works in several ways to reduce ammonia:
§ Speeds up transit time and reduces constipation (the laxative effect clearing the ammonia before it is absorbed)
§ Promotes bacterial uptake of ammonia to be used for protein synthesis
§ Changes the pH of the contents of the intestine to become more acidic, killing ammonia-producing bacteria

Rifaximin is the usual choice of antibiotic as it is poorly absorbed and stays in the gastrointestinal tract. Neomycin and metronidazole are alternatives.

Question 43

Management of primary sclerosing cholingitis

Answer 43

Endoscopic retrograde cholangio-pancreatography (ERCP) may be used to treat dominant strictures. This involves inserting an endoscope down the oesophagus, past the stomach, to the duodenum and the opening of the common bile duct (the sphincter of Oddi). This gives the operator access to the biliary system. Strictures can be dilated. Stents can be inserted to keep the ducts open. Antibiotics are given alongside ERCP to reduce the risk of infection (bacterial cholangitis).

Other aspects of management include:
• Colestyramine for symptoms of pruritus (itchy skin) (a bile acid sequestrant that reduces intestinal absorption of bile acids)
• Replacement of fat-soluble vitamins
• Monitoring for complications such as cholangiocarcinoma, cirrhosis and oesophageal varices

Question 44

Treatment of primary biliary cholingitis

Answer 44

Treatment
Ursodeoxycholic acid is the most essential treatment to remember in primary biliary cholangitis. It is a non-toxic, hydrophilic bile acid that protects the cholangiocytes from inflammation and damage. It makes the bile less harmful to the epithelial cells of the bile ducts. It slows the disease progression and improves outcomes.

Other treatments include:
• Obeticholic acid (where UDCA is inadequate or not tolerated – although it can have significant adverse effects)
• Colestyramine for symptoms of pruritus (a bile acid sequestrant that reduces intestinal absorption of bile acids)
• Replacement of fat-soluble vitamins
• Immunosuppression (e.g., with steroids) is considered in some patients
• Liver transplant in end-stage liver disease

Question 45

Management of spontaneous bacterial peritonitis

Answer 45

Management involves:
§ Taking a sample of ascitic fluid for culture before giving antibiotics

§ Intravenous broad-spectrum antibiotics according to local policies (e.g., piperacillin with tazobactam)

Question 46

Hepatorenal syndrome drug options

Answer 46

Terlipressin and albumin

Question 47

Management of Wilson’s disease

Answer 47

Management
Treatment is with copper chelation using either:
○ Penicillamine
○ Trientine

Other treatments include:
§ Zinc salts (inhibit copper absorption in the gastrointestinal tract)
§ Liver transplantation

Question 48

Barrett’s oesophagus treatment

Answer 48

Protein pump inhibitors
Protein pump inhibitors (PPIs) are recommended in all patients with BO. PPIs prevent acid production within the stomach through inhibition of H+/K+ ATPases in parietal cells. This reduces the acidity of the refluxate and therefore the damage to the lower oesophageal mucosa. PPI reduce risk of both high grade dysplasia and oesophageal carcinoma.

Question 49

Treatment for GORD

Answer 49

• Lifestyle changes
• Reviewing medications (e.g., stop NSAIDs)
• Antacids (e.g., Gaviscon, Pepto-Bismol and Rennie) – short term only
• Proton pump inhibitors (e.g., omeprazole and lansoprazole)
• Histamine H2-receptor antagonists (e.g., famotidine)
• Surgery

Question 50

Antidote for paracetamol overdose

Answer 50

N-acetylcysteine

Question 51

Gut motility prokinetics

Answer 51

• Prokinetics – strengthen lower oesophagus causing stomach to empty faster emptying
• Relieve GI symptoms e.g. gastric stasis due to opioids, gastropoeresis, hepatomegaly , functional obstruction
• Metoclopramide
• Domperidone
• Erythromycin

Question 52

Vitamin B1 replacement

Answer 52

IV pabrinex
Oral thiamine

Question 53

Cyclizine

Answer 53

• Mode of action: Cyclizine is an antihistaminic, antimuscarinic, anti-emetic which exerts its action on the vomiting centre.

• Preparations available: 50mg tablets, 50mg/ml injection

• Dose: 50mg tds PO/IV/IM/SC or 150mg continuous subcutaneous infusion
over 24 hours

• Side effects: drowsiness, urinary retention, dry mouth, blurred vision, and gastro-intestinal disturbances

Question 54

Metoclopramide

Answer 54

• Mode of action: Metoclopramide is a prokinetic anti-emetic and is a combined D2-receptor antagonist and 5HT4 receptor agonist. At high doses it also acts as a 5HT3 antagonist. It crosses the blood brain barrier (BBB).

• Preparations available: 10mg tablets, 5mg/5ml solution, 5mg/ml injection
• Dose: 10mg tds PO/IV/IM for up to 5 days.

• Side effects: extrapyramidal effects (more frequent with high doses and in children and young adults due to it crossing the BBB), hyperprolactinaemia, akathisia. It doesn’t work well with Cyclizine

Question 55

Domperidone

Answer 55

Anti ametic

• Mode of action: Domperidone is a D2-receptor antagonist with some prokinetic action.
• Preparations available: 10mg tablet, 5mg/5ml suspension. The suppositories have been discontinued.
• Dose: 10 TDS times a day PO for up to 7 days.
• Side effects: rarely gastro-intestinal disturbances (including cramps), raised prolactin concentration

Question 56

Prochloroperazine

Answer 56

• Mode of Action: Dopamine antagonist, some antimuscarinic and antihistaminic effects.
• Preparations available: 5mg tablets, 3mg buccal tablets, 1mg/ml syrup, 12.5mg/ml injection
• Dose: 5-10mg BD / TDS orally, 3-6mg bd – tds buccally, 12.5mg IM • Side effects: drowsiness, extrapyramidal effects

Question 57

Ondansetron

Answer 57

Anti ametic

• Mode of action: Ondansetron is a 5HT3 receptor antagonist which prevents release of 5HT (serotonin) from enterochromaffin cells in the duodenum.

• Preparations available: 4mg and 8mg tablets/oral lyophilisates, 4mg/5ml syrup, 2mg/ml injection, 16mg suppository

• Dose: 8mg IV or PO prior to treatment then 8mg bd PO usually for 48 hours or 16mg od PR

• Side effects: include mild headache, CONSTIPATION, QT ELONGATION and transient elevations of serum aminotransferases. These can be treated symptomatically with simple analgesics and laxatives. Patients experiencing side effects due to ondansetron may be offered an alternative 5HT3 receptor antagonist such as granisetron (IV 1-3mg oral 1- 2mg daily)

Question 58

Aprepitant

Answer 58

Aprepitant
Anti ametic used in chemo clinics

• Mode of Action: NK1 receptor antagonist – blocks action of substance P in the CTZ

• Preparations available: 125mg and 80mg capsules, Powder for oral suspension (25mg/ml once reconstituted) (not stocked by many Trusts)

• Dose: 125mg 1 hour before treatment, then 80mg daily for two days.

• Side effects: hiccups, dyspepsia, diarrhoea, constipation, anorexia, asthenia, headache, dizziness.

Question 59

Dexamethasone

Answer 59

Dexamethasone

• Mode of action: Dexamethasone is a corticosteroid which also has anti-emetic action

• Preparations available: 2mg & 500 microgram dexamethasone tablets, 2mg/5ml dexamethasone sodium phosphate oral solution. Injection dexamethasone base - 3.8mg/ml injection (as 5mg/ml dexamethasone sodium phosphate).

• Dose: varies - see individual treatment regimens

• Side effects: adverse effects of single dexamethasone doses are rare, although elevations of serum glucose levels, epigastric discomfort and sleep disturbances occur - see product literature for more details.

Question 60

Olanzipine

Answer 60

Olanzapine

•Mode of Action: Olanzapine is an atypical anti psychotic agent of the thienobenzodiazepine class that has the ability to block many different receptors, which explains its antiemetic properties. Olanzapine targets dopaminergic (D1, D2, D3, D4), serotonergic (5-HT2A, 5-HT2C, 5-HT3, 5-HT6), adrenergic (á1), histaminergic (H1), and muscarinic (m1, m2, m3, m4) receptors.
• Preparationsavailable:2.5mg,10mgtabletsand5mgorodispersibletablets

•Dose:5-10mg od starting on the day of chemotherapy for 4 days. The dose may be increased up to a maximum of 20mg per day.

• Side effects: drowsiness,weightgain,eosinophilia,elevatedprolactin,cholesterol,glucoseand triglyceride levels glucosuria, increased appetite, dizziness, akathisia, parkinsonism, leukopenia, neutropenia, dyskinesia, orthostatic hypotension, anticholinergic effects, transient asymptomatic elevations of hepatic aminotransferases, rash, asthenia, fatigue pyrexia, arthralgia, increased alkaline phosphatase, high gamma glutamyltransferase, high uric acid, high creatinine phosphokinase and oedema.