Pituitary Disorders
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Adults 2019 Edition
Includes prolactinoma, anterior hypothyroid hypopituitarism and diabetes insipidus.
PROLACTINOMA
ICD-10 Code: D35.2 + (M8271/0)
DESCRIPTION
- Prolactinoma is the most common functioning pituitary tumour.
Investigations
- Serum prolactin, β-hCG.
Note
There are numerous causes of hyperprolactinaemia other than a prolactinoma, so secondary causes must be excluded e.g. pregnancy, medicines, physiological, hypothyroidism, chronic renal failure and tumours.
In patients with prolactinoma, serum prolactin levels are usually elevated ≥ 4 times the upper limit of the normal reference range for the laboratory method used. Lesser degree of elevation of serum prolactin may also be found in patients with other pituitary tumours associated with pituitary stalk compression.
MEDICINE TREATMENT
Dopamine agonist therapy is the treatment of choice.
- Bromocriptine, oral, 1.25 mg at bedtime with a snack.
- Initial maintenance dose: increase dose to 2.5 mg 12 hourly with food and check prolactin 4 weeks later.
- Higher doses may be needed.
- GIT side effects are minimised by giving doses with food.
- If total dose of 10 mg does not normalise prolactin, refer.
REFERRAL
- All tumours, once causes of secondary hyperprolactinaemia have been sought and excluded.
- Intolerance to bromocriptine.
- Unexplained hyperprolactinemia.
Urgent
- Visual disturbances especially those suggesting compression of optic chiasm.
- Pituitary apoplexy.
ANTERIOR HYPOPITUITARISM
ICD-10 Code: E23.0-3/E28.3/E29.1
DESCRIPTION
- Absent or diminished secretion of one or more anterior pituitary hormones due to primary damage of the anterior pituitary gland or secondary to hypothalamic dysfunction, which may result in hypothyroidism and/or hypoadrenalism and/or hypogonadism or growth retardation in children.
GENERAL MEASURES
- Surgery is required for large tumours, pituitary apoplexy, and hormone secreting tumours (except for most patients with prolactinomas, who generally respond well to medical therapy).
- Radiotherapy may be required in selected patients
- A notification bracelet is needed.
MEDICINE TREATMENT
Acute crisis
- Treat as for acute crisis in Adrenal Insufficiency (Addison’s Disease).
Chronic
Hypoadrenalism
Hypothyroidism
- See Hypothyroidism.
Hypogonadism
- Individualise dosage and need for replacement according to age, symptoms, etc.
Women:
As for postmenopausal HT, see Menopause and perimenopausal syndrome.
Men:
- Testosterone cypionate, IM, 200–300 mg every 3–4 weeks.
See Androgen deficiency.
REFERRAL
- All diagnosed patients for initial assessment.
DIABETES INSIPIDUS (POSTERIOR HYPOPITUITARISM)
ICD-10 Code: E23.2
DESCRIPTION
- Damage to the posterior pituitary leading to deficient production of antidiuretic hormone.
- Characterised by the passage of large amounts of dilute urine, usually > 2.5 litres daily.
- Causes include head trauma and neurosurgery but most cases are idiopathic.
Consultation with a specialist is recommended.
GENERAL MEASURES
- Rehydration with water or hypotonic fluids.
MEDICINE TREATMENT
Postoperative or acutely ill patients:
- Desmopressin, IV/SC, 2-4 mcg daily, either as a single dose or in 2 divided doses.
OR
- Desmopressin, nasal spray, 10-40 mcg daily, either as a single dose or in 2-3 divided doses.
OR
- Desmopressin, oral, 0.05 mg, 8-12 hourly.
- Optimal dose: 0.1-0.8 mg daily.
- Adjust dose according to response to a maximum of 1.2 mg daily in divided doses.
- Click here for Circular 2020/11/26/EDP/01 - Notice: Recommended therapeutic alternative for desmopressin nasal formulations.
If patient has a normal thirst mechanism, and does not receive IV fluids for other purposes:
- oral, intranasal, or IV/SC dosing can be used; and
- keep urine osmolality at 450–600 mOsm/kg
If patient requires IV fluids and/or is unable to regulate total fluid intake by thirst mechanism:
- IV dosing is preferred; and
- continuously adjust the level of antidiuresis to maintain hydration and plasma sodium within the normal.
Replacement therapy:
- Desmopressin, nasal spray, 10-40 mcg daily, either as a single dose or in 2-3 divided doses.
- Adjust morning and evening doses separately for appropriate diurnal rhythm of water turnover
OR
- Desmopressin, oral, 0.05 mg, either as a single dose or in 2-3 divided doses.
- Optimal dose: 0.1-0.8 mg daily.
- Adjust dose according to response to a maximum of 1.2 mg daily in divided doses.
REFERRAL
- All patients diagnosed or suspected
- Water deprivation may be necessary to confirm the diagnosis. Careful monitoring of electrolytes and exclusion of fluid overload while on therapy is essential to determine the appropriate dose.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Adults 2024 Edition