THERAPEUTICS

Thyroid hormones

Mechanism of action

Synthetic thyroxine.

Indications

Hypothyroidism, diffuse non-toxic goitre, thyroid carcinoma.

Preparations and dose

Levothyroxine sodium (thyroxine)

Tablets: 25 /ig, 50 μg 100 μg.

1.6 μg/kg/day body weight (100-125 μg for an average sized adult); 25 μg/day in elderly or those with ischaemic heart disease increased in steps of 25-50 μg every 3-6 weeks until the serum TSH values return to the refer-ence range.

Side-effects

These usually occur at excessive dosage and at start of therapy with rapid increase in metabolism. Arrhythmias, palpitations, skeletal muscle cramps and weakness, vomiting, diarrhoea, tremors, restlessness, headache, flush-ing, sweating, fever, excessive loss of weight and, sometimes, anginal pain where there is latent myocardial ischaemia.

Cautions/contraindications

Panhypopituitarism or predisposition to adrenal insufficiency from other causes (initiate corticosteroid therapy before starting levothyroxine), lower starting dose in the elderly or cardiovascular disease, diabetes mellitus (dosage increase may be needed for antidiabetic drugs including insulin). Contraindicated in thyrotoxicosis unless with carbimazole (see below).

Antithyroid drugs

Mechanism of action

Interfere with synthesis of thyroid hormones.

Indications

Long-term management of thyrotoxicosis and to prepare patients for thyroid-ectomy. May be given with propranolol, 40 mg three times daily, for initial symptom control.

Preparations and dose

Carbimazole

Tablets: 5 mg, 20 mg.

Most commonly used drug for thyrotoxicosis in the UK. Initial treatment 15-40 mg daily; higher doses required in severe disease. This dose is con-tinued until the patient becomes euthyroid, usually after 4-8 weeks, and the dose is then gradually reduced over 6-24 months to a maintenance dose of 5-15 mg daily. A combination of carbimazole, 40-60 mg daily with levo-thyroxine 50-150 μg daily is sometimes used in a blocking-replacement regimen (not in pregnancy).

Propylthiouracil

Tablets: 50 mg.

Dosing schedule is as for carbimazole but initial treatment is 200-400 mg daily and maintenance dose 50-150 mg daily.

Side-effects

Bone marrow suppression particularly with carbimazole; patients should be asked to report symptoms and signs suggestive of infection, especially sore throat. A white cell count should be performed if there is any clinical evidence of infection, and treatment should be stopped immediately if there is clinical or laboratory evidence of neutropenia. Nausea, gastrointestinal disturbance, headache, rashes and pruritus occur with carbimazole; cutaneous vasculitis, hepatic necrosis, nephritis and lupus-like syndrome with propylthiouracil.

Cautions/contraindications

Liver disorders; overtreatment can result in rapid development of hypothyroidism.

Corticosteroids

Mechanism of action

Replacement therapy The adrenal cortex normally secretes hydrocortisone (cortisol) which has glucocorticoid activity and weak mineralocorticoid activ-ity. It also secretes the mineralocorticoid aldosterone. In primary adrenal insufficiency physiological replacement is best achieved with a combination of hydrocortisone and the mineralocorticoid fludrocortisone; hydrocortisone alone does not usually provide sufficient mineralocorticoid activity for com-plete replacement. In hypopituitarism glucocorticoids are given but aldoster-one is not necessary as production is regulated by the renin-angiotensin system.

Anti-inflammatory actions include induction of the synthesis of IkB, an inhibitory protein which binds NF-Kappa B.

Indications

■ A wide variety of inflammatory conditions of the joints, lungs, skin and bowel, acute transplant rejection, autoimmune conditions, nephritic/ nephrotic syndrome (particularly in children), cerebral oedema, acute hypersensitivity reactions such as angio-oedema of the upper respiratory tract and anaphylactic shock

■ For replacement therapy in adrenal insufficiency and hypopituitarism. The type of steroid preparation used depends on the indication, e.g. dexa-methasone is a very potent steroid with insignificant mineralocorticoid activity (see below) and this makes it particularly suitable for high-dose therapy in conditions where fluid retention (mineralocorticoid side-effect) would be a disadvantage, e.g. cerebral oedema. Prednisolone has predominantly gluco-corticoid activity and is the corticosteroid most commonly used by mouth for long-term disease suppression. The relatively high mineralocorticoid activity of cortisone and hydrocortisone, and the resulting fluid retention, make them unsuitable for disease suppression on a long-term basis. Hydrocortisone is used for adrenal replacement therapy and intravenously in the emergency management of some conditions, e.g. severe ulcerative colitis, anaphylactic shock. Corticosteroids are also used by inhalation in asthma, by rectal admin-istration in inflammatory bowel disease, and topically in the treatment of inflammatory conditions of the skin. These preparations are not discussed in this section.

Preparations and dose

The equivalent anti-inflammatory doses of corticosteroids and their mineralocorticoid activity are shown in Table 14.19.

Prednisolone

Tablets: 1 mg, 5 mg, 25 mg; Soluble tablets: 5 mg; Enteric-coated tablets: 2.5 mg, 5 mg.

Oral Usual treatment dose, initially 10-40 mg daily, up to 60 mg in severe disease as a single dose after breakfast. Maintenance usually 2.5-15 mg.

Hydrocortisone

Tablets: 10 mg, 20 mg; Inịection: 100 mg powder for reconstitution.

Oral Replacement therapy: 20-30 mg daily in divided doses.

Table 14.19 Equivalent anti-inflammatory doses of corticosteroids

Mineralocorticoid activity

Prednisolone 5 mg

Slight

= Betamethasone 750 μg

Negligible

= Cortisone acetate 25 mg

High

= Deflazacort 6 mg

Slight

= Dexamethasone 750 μg

Negligible

= Hydrocortisone 20 mg

High

= Methylprednisolone 4 mg

Slight

= Triamcinolone 4 mg

Slight

IV/IM 100-500 mg, three to four times daily or as required, by a slow bolus or as an infusion in sodium chloride 0.9% or glucose 5%.

Dexamethasone

Tablets: 500 μg 2 mg; Oral solution: 2 mg/5 mL; Inịection: 4 mg/mL, 24 mg/5 mL.

Oral 0.5-10 mg daily in divided doses.

IV/IM Initially 0.5-20 mg daily in divided doses; intravenous injection must be given over at least 3-5 minutes or as an infusion in sodium chloride 0.9% or glucose 5%.

Methylprednisolone

Tablets: 2 mg, 4 mg, 16 mg, 100 mg; Inịection: 40 mg, 125 mg, 500 mg, 1 g, 2 g vial.

Oral Usual range 2-40 mg daily.

IV/IM Initially 10-500 mg daily, dose depends on condition. Slow intravenous injection or infusion.

Side-effects

Glucocorticoid side-effects include diabetes and osteoporosis (p. 639).

Precautions for patients taking prolonged therapy with corticosteroids are discussed on page 640. Mineralocorticoid side-effects include hypertension, sodium and water retention and potassium loss.

Cautions/contraindications

Untreated systemic infection, avoid live virus vaccines in those receiving immunosuppressive doses.

Ebook Essentials of Kumar and Clark's Clinical Medicine, 5e

1. Ethics and communication

Ethics and communication

2. Infectious diseases

Infectious diseases

3. Gastroenterology and nutrition

Gastroenterology and nutrition

4. Liver, biliary tract and pancreatic disease

Liver, biliary tract and pancreatic disease
LIVER BIOCHEMISTRY AND LIVER FUNCTION TESTS
SYMPTOMS AND SIGNS OF LIVER DISEASE
JAUNDICE
HEPATITIS
NON - ALCOHOLIC FATTY LIVER DISEASE (NAFLD)
CIRRHOSIS
COMPLICATIONS AND EFFECTS OF CIRRHOSIS
LIVER TRANSPLANTATION
TYPES OF CHRONIC LIVER DISEASE AND CIRRHOSIS
PRIMARY SCLEROSING CHOLANGITIS
BUDD - CHIARI SYNDROME
LIVER ABSCESS
LIVER DISEASE IN PREGNANCY
LIVER TUMOURS
GALLSTONES
THE PANCREAS
CARCINOMA OF THE PANCREAS
NEUROENDOCRINE TUMOURS OF THE PANCREAS

5. Haematological disease

Haematological disease
ANAEMIA
Assessment and treatment of suspected neutropenic sepsis
HAEMOLYTIC ANAEMIA
INHERITED HAEMOLYTIC ANAEMIAS
ACQUIRED HAEMOLYTIC ANAEMIA
MYELOPROLIFERATIVE DISORDERS
THE SPLEEN
BLOOD TRANSFUSION
THE WHITE CELL
HAEMOSTASIS AND THROMBOSIS
THROMBOSIS
THERAPEUTICS

6. Malignant disease

Malignant disease
MYELOABLATIVE THERAPY AND HAEMOPOIETIC STEM CELL TRANSPLANTATION
THE LYMPHOMAS
THE PARAPROTEINAEMIAS
PALLIATIVE MEDICINE AND SYMPTOM CONTROL

7. Rheumatology

Rheumatology
COMMON INVESTIGATIONS IN MUSCULOSKELETAL DISEASE
COMMON REGIONAL MUSCULOSKELETAL PROBLEMS
BACK PAIN
OSTEOARTHRITIS
INFLAMMATORY ARTHRITIS
THE SERONEGATIVE SPONDYLOARTHROPATHIES
Clinical features, Investigations
INFECTION OF JOINTS AND BONES
AUTOIMMUNE RHEUMATIC DISEASES
SYSTEMIC INFLAMMATORY VASCULITIS
DISEASES OF BONE
THERAPEUTICS

8. Water, electrolytes and acid–base balance

WATER AND ELECTROLYTE REQUIREMENTS
BODY FLUID COMPARTMENTS
REGULATION OF BODY FLUID HOMEOSTASIS
PLASMA OSMOLALITY AND DISORDERS OF SODIUM REGULATION
DISORDERS OF POTASSIUM REGULATION
DISORDERS OF MAGNESIUM REGULATION
DISORDERS OF ACID - BASE BALANCE
THERAPEUTICS

9. Renal disease

Renal disease
INVESTIGATION OF RENAL DISEASE
GLOMERULAR DISEASES
NEPHROTIC SYNDROME
URINARY TRACT INFECTION
TUBULOINTERSTITIAL NEPHRITIS
HYPERTENSION AND THE KIDNEY
RENAL CALCULI AND NEPHROCALCINOSIS
URINARY TRACT OBSTRUCTION
ACUTE RENAL FAILURE/ACUTE KIDNEY INJURY
CHRONIC KIDNEY DISEASE
RENAL REPLACEMENT THERAPY
CYSTIC RENAL DISEASE
TUMOURS OF THE KIDNEY AND GENITOURINARY TRACT
DISEASES OF THE PROSTATE GLAND
TESTICULAR TUMOUR
URINARY INCONTINENCE

10. Cardiovascular disease

COMMON PRESENTING SYMPTOMS OF HEART DISEASE
INVESTIGATIONS IN CARDIAC DISEASE
CARDIAC ARRHYTHMIAS
HEART FAILURE
ISCHAEMIC HEART DISEASE
RHEUMATIC FEVER
VALVULAR HEART DISEASE
PULMONARY HEART DISEASE
MYOCARDIAL DISEASE
CARDIOMYOPATHY
PERICARDIAL DISEASE
SYSTEMIC HYPERTENSION
ARTERIAL AND VENOUS DISEASE
ELECTRICAL CARDIOVERSION
DRUGS FOR ARRHYTHMIAS
DRUGS FOR HEART FAILURE
DRUGS AFFECTING THE RENIN - ANGIOTENSIN SYSTEM
NITRATES, CALCIUM - CHANNEL BLOCKERS AND POTASSIUM - CHANNEL ACTIVATORS

11. Respiratory disease


Respiratory disease
TUBERCULOSISnd
DIFFUSE DISEASES OF THE LUNG PARENCHYMA
OCCUPATIONAL LUNG DISEASE
CARCINOMA OF THE LUNG
DISEASES OF THE CHEST WALL AND PLEURA
DISORDERS OF THE DIAPHRAGM

12. Intensive care medicine

Intensive care medicine

13. Drug therapy, poisoning, and alcohol misuse

Drug therapy, poisoning, and alcohol misuse

14. Endocrine disease

Endocrine disease
PITUITARY HYPERSECRETION SYNDROMES
THE THYROID AXIS
MALE REPRODUCTION AND SEX
FEMALE REPRODUCTION AND SEX
THE GLUCOCORTICOID AXIS
THE THIRST AXIS
DISORDERS OF CALCIUM METABOLISM
DISORDERS OF PHOSPHATE CONCENTRATION
ENDOCRINOLOGY OF BLOOD PRESSURE CONTROL
DISORDERS OF TEMPERATURE REGULATION
THERAPEUTICS

15. Diabetes mellitus and other disorders of metabolism

DIABETES MELLITUS
DIABETIC METABOLIC EMERGENCIES
COMPLICATIONS OF DIABETES
SPECIAL SITUATIONS
HYPOGLYCAEMIA IN THE NON - DIABETIC
DISORDERS OF LIPID METABOLISM
THE PORPHYRIAS

16. The special senses

THE EAR
THE NOSE AND NASAL CAVITY
THE THROAT
THE EYE

17. Neurology

COMMON NEUROLOGICAL SYMPTOMS
COORDINATION OF MOVEMENT
THE CRANIAL NERVES
COMMON INVESTIGATIONS IN NEUROLOGICAL DISEASE
UNCONSCIOUSNESS AND COMA
STROKE AND CEREBROVASCULAR DISEASE
EPILEPSY AND LOSS OF CONSCIOUSNESS
NERVOUS SYSTEM INFECTION AND INFLAMMATION
HYDROCEPHALUS
HEADACHE, MIGRAINE AND FACIAL PAIN
SPINAL CORD DISEASE
DEGENERATIVE NEURONAL DISEASES
DISEASES OF THE PERIPHERAL NERVES
MUSCLE DISEASES
MYOTONIAS
DELIRIUM
THERAPEUTICS

18. Dermatology

Dermatology

KEYWORD : Phác Đồ Chữa Bệnh, Bệnh Viện Bạch Mai, Từ Dũ , 115, Bình Dân, Chấn thương chỉnh hình, Chợ Rẫy, Đại học Y Dược, Nhân Dân Gia Định, Hoàn Mỹ, Viện Pasteur, Nhi Đồng Ung bướu, Quân Đội 103, 108,Phụ Sản Trung Ương, Bộ Y Tế,Phòng Khám, Hà Nội, Hải Dương, Thái Bình, Hồ Chí Minh, Sài Gòn, Đà Nẵng, Huế, Vinh, Đồng Nai, Bình Dương, Hải Phòng, Quảng Ninh, Hiệu Quả Cao, Chữa Tốt, Khỏi Bệnh, Là Gì, Nguyên Nhân, Triệu Chứng, Ăn Uống, Cách Chữa, Bài Thuốc
Thông Tin Trên Web Là Tài Liệu Lưu Hành Nội Bộ Cho Các Bạn Sinh Viên - Y, Bác Sĩ Tham Khảo : Liên Hệ : Maikhanhdu@gmail.com