Indapamide is a mild thiazide-like diuretic with hypotensive effect, and compared to other thiazides, it is reported to also have less metabolic derangements. However, it may have beneficial hypo-calciuric effects that are often associated with thiazides, thus, in this case, we would recommend prescribing this to the patient.

High Altitude Cerebral Oedema (HACE) is a severe and potentially fatal manifestation of high altitude illness and is often characterized by ataxia, fatigue, and altered mental status. HACE is often thought of as an extreme form/end-stage of Acute Mountain Sickness (AMS). Although HACE represents the least common form of altitude illness, it may progress rapidly to coma and death as a result of brain herniation within 24 hours, if not promptly diagnosed and treated.

HACE generally occurs after 2 days above 4000m but can occur at lower elevations (2500m) and with faster onset. Some, but not all, individuals will suffer from symptoms of AMS such as headache, insomnia, anorexia, nausea prior to transitioning to HACE. Some may also have concomitant High Altitude Pulmonary Oedema (HAPE). HACE in isolation is rare, but the absence of concomitant HAPE or symptoms of AMS prior to deterioration does not rule-out the presence of HACE.

Most cases develop as a progression of AMS and will include a history of recent ascent to altitude and prior complaints/findings of AMS including a headache, fatigue, nausea, insomnia, and/or light-headedness. Some may also have signs/symptoms of HAPE. Transition to HACE is heralded by signs of encephalopathy including ataxia (usually the earliest clinical finding) and altered mentation which may range from mild to severe. Other symptoms may include a more severe headache, difficulty speaking, lassitude, a decline in the level of consciousness, and/or focal neurological deficits or seizures.

The mainstay of treatment is the immediate descent of at least 1000m or until symptoms improve. If descent is not an option, one may use a portable hyperbaric chamber and/or supplemental oxygen to temporize illness, but this should never replace or delay evaluation/descent when possible. If available, dexamethasone 8mg for one dose, followed by 4mg every 6 hours should be given to adults via PO, IM, or IV routes.
Acetazolamide has proven to be beneficial in only a single clinical study. The suggested dosing regimen for Acetazolamide is 250 mg PO, given twice daily. Though effective in alleviating or temporizing symptoms, none of the adjunct treatment modalities are definitive or a replacement for an immediate descent.

There are two main reasons for using combinations of chemotherapeutic agents rather than single agents. First, different drugs exert their effects through different mechanisms, therefore, carefully combining them will increase the number of tumour cells killed in each cycle as well as decrease their chances of developing drug resistance. Second, there may be an even greater effect with drugs that are synergistic.

Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs) and is characterized by the destruction of thyroid cells by various cell- and antibody mediated immune processes. It usually presents with hypothyroidism, insidious in onset, with signs and symptoms slowly progressing over months to years.

The diagnosis of Hashimoto thyroiditis relies on the demonstration of circulating antibodies to thyroid antigens (mainly thyroperoxidase and thyroglobulin) and reduced echogenicity on thyroid sonogram in a patient with proper clinical features.

The risk factors for bladder cancer are:

1. Smoking
2. Exposure to aniline dyes in the printing and textile industry
3. Exposure to rubber manufacturing
4. Cyclophosphamides
5. Schistosomiasis.

Tumour marker CA 15-3 is mostly associated with breast cancer.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Pulmonary alveolar proteinosis (PAP) is a lung condition that is caused by a build-up of proteins and other substances in the alveoli. The alveoli are the part of the lungs that contain air. PAP has the following symptoms:
Shortness of breath, also called dyspnoea
Chest pain or tightness
Fever
Weight loss
Cough (sometimes, but not always)
Low levels of oxygen in the blood
Nail clubbing (abnormal growth of toenails or fingernails)

Serologic studies are generally not useful for PAP. Flexible bronchoscopy with bronchoalveolar lavage (BAL) remains the criterion standard. Elevated levels of the proteins SP-A and SP-D in serum and BAL fluid may be useful. Elevated titer of neutralizing autoantibody against GM-CSF (immunoglobulin G [IgG] isotype) in serum and BAL fluid may be useful. Recent studies have proposed that deficiency of GM-CSF causes pulmonary alveolar proteinosis (PAP); all patients studied had the antibody to GM-CSF. Serum lactate dehydrogenase (LDH) level is usually elevated, but this finding is nonspecific.

High-resolution computed tomography (HRCT) scan of the chest demonstrates areas of patchy ground-glass opacification with smooth interlobular septal thickening and intralobular interstitial thickening, which produces a polygonal pattern referred to as crazy paving.

Light microscopy of the lung parenchymal tissue shows alveoli filled with a granular PAS base-reactive and diastase-resistant eosinophilic material.

The patient has Acromegaly.
Acromegaly is a chronic disorder characterised by growth hormone (GH) hypersecretion, predominantly caused by a pituitary adenoma.

Random GH level testing is not recommended for diagnosis given the pulsatile nature of secretion. Stress, physical exercise, acute critical illness and fasting state can cause a physiological higher peak in GH secretion.

Pegvisomant is a US Food and Drug Administration-approved treatment for use after surgery. In a global non-interventional safety surveillance study, pegvisomant normalised IGF-1 in 67.5% of patients after 5 years (most likely due to lack of dose-up titration), and also improved clinical symptoms. Pegvisomant improves insulin sensitivity, and long-term follow-up showed significantly decreased fasting glucose over time, while the first-generation SRL only have a marginal clinical impact on glucose homeostasis in acromegaly. Pegvisomant does not have any direct anti-proliferative effects on pituitary tumour cells, but tumour growth is rare overall.

Cisplatin is a cytotoxic agent that acts by causing cross-linking in DNA. Its adverse effects include ototoxicity, peripheral neuropathy, hypomagnesaemia, etc.

The causative cytotoxic agents acting through the other aforementioned MOAs are as follows:

1. Doxorubicin: Stabilizes DNA topoisomerase II complex and inhibits DNA and RNA synthesis.

2. Hydroxyurea (hydroxycarbamide): Inhibits ribonucleotide reductase, decreasing DNA synthesis.

3. Mercaptopurine (6-MP): Purine analogue that is activated by HGPRTase, decreasing purine synthesis.

4. Vincristine, vinblastine: Inhibits formation of microtubules.

Carcinoembryonic antigen (CEA) is a known tumour marker for colorectal cancer. It is not used diagnostically, but in patients with a known diagnosis of colorectal cancer associated with raised CEA levels, it can be used to monitor disease activity and help with the early identification of disease recurrence.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Patients with active cancer are at a continuous risk of having venous thromboembolism (VTE), such as DVT. Therefore, a six-month course of an anticoagulant such as LMWH is recommended. LMWH is the drug of choice since its side effects can be reversed and it can be stopped easily in case of a cancer-related bleed, for example, massive haemoptysis in a patient with lung cancer.

Type 1 diabetes is a chronic illness characterized by the body’s inability to produce insulin due to the autoimmune destruction of the beta cells in the pancreas. Approximately 95% of patients with type 1 DM have either HLA-DR3 or HLA-DR4. Although the genetic aspect of type 1 DM is complex, with multiple genes involved, there is a high sibling relative risk. Whereas dizygotic twins have a 5-6% concordance rate for type 1 DM, monozygotic twins will share this diagnosis more than 50% of the time by the age of 40 years.

Senile cataract is an age-related, vision-impairing disease characterized by gradual progressive clouding and thickening of the lens of the eye. Patients with senile cataracts often present with a history of gradual progressive visual deterioration and disturbance in night and near vision.

The typical “rheumatoid effusion” is a sterile exudative fluid with low pH (<7.3), low glucose (<60 mg. dL−1) and elevated lactate dehydrogenase (may be >700 IU). It should initially be treated with NSAIDs. Decortication should be reserved in patients with thickened pleura who have symptomatic dyspnoea.

Blue tinge of vision/cyanopsia is caused due to the intake of sildenafil citrate.

Sildenafil citrate (Viagra) is the first oral drug to be widely approved for the treatment of erectile dysfunction.
It is a potent and selective inhibitor of type-V phosphodiesterase, the primary form of the enzyme found in human penile erectile tissue, thereby preventing the breakdown of cyclic guanosine monophosphate (cGMP), the intracellular second messenger of nitric oxide.

Uses:
It is used for the treatment of erectile dysfunction, idiopathic pulmonary hypertension, premature ejaculation, high altitude illness, penile rehabilitation after radical prostatectomy, angina pectoris, and lower urinary tract symptoms.

Adverse effects:
Mild headache, flushing, dyspepsia, cyanopsia, back pain, and myalgias – due to a high concentration of PDE11 enzyme in skeletal muscle, which shows significant cross-reactivity with the use of tadalafil.
It can also cause hypotension, dizziness, and rhinitis.

Note: Xanthopsia (yellow-green vision) may occur secondary to treatment with digoxin.

Criteria for the diagnosis of diabetes

1. A1C ≥6.5%. The test should be performed in a laboratory using a method that is certified and standardized.*
OR
2. Fasting glucose ≥126 mg/dl (7.0 mmol/l). Fasting is defined as no caloric intake for at least 8 h.*
OR
3. 2-h plasma glucose ≥200 mg/dl (11.1 mmol/l) during an OGTT. The test should be performed as described by the World Health Organization, using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water.*
OR
4. In a patient with classic symptoms of hyperglycaemia or hyperglycaemic crisis, a random plasma glucose ≥200 mg/dl (11.1 mmol/l).
*In the absence of unequivocal hyperglycaemia, criteria 1–3 should be confirmed by repeat testing.

Retinitis pigmentosa primarily affects the peripheral retina resulting in tunnel vision. Night blindness is often the initial sign. Tunnel vision occurs due to loss of the peripheral retina (occasionally referred to as funnel vision).
Fundoscopy exam reveals black bone spicule-shaped pigmentation in the peripheral retina, and mottling of the retinal pigment epithelium.

Cyanide poisoning:
Aetiology:
Smoke inhalation, suicidal ingestion, and industrial exposure (specific industrial processes involving cyanide include metal cleaning, reclaiming, or hardening; fumigation; electroplating; and photo processing) are the most frequent sources of cyanide poisoning. Treatment with sodium nitroprusside or long-term consumption of cyanide-containing foods is a possible source.
Cyanide exposure most often occurs via inhalation or ingestion, but liquid cyanide can be absorbed through the skin or eyes. Once absorbed, cyanide enters the blood stream and is distributed rapidly to all organs and tissues in the body. 

Pathophysiology:
Inside cells, cyanide attaches itself to ubiquitous metalloenzymes, rendering them inactive. Its principal toxicity results from inactivation of cytochrome oxidase (at cytochrome a3), thus uncoupling mitochondrial oxidative phosphorylation and inhibiting cellular respiration, even in the presence of adequate oxygen stores.

Presentation:
• ‘Classical’ features: brick-red skin, smell of bitter almonds
• Acute: hypoxia, hypotension, headache, confusion
• Chronic: ataxia, peripheral neuropathy, dermatitis

Management:
• Supportive measures: 100% oxygen, ventilatory assistance in the form of intubation if required.
• Definitive: Hydroxocobalamin (iv) is considered the drug of choice and is approved by the FDA for treating known or suspected cyanide poisoning.
• Coadministration of sodium thiosulfate (through a separate line or sequentially) has been suggested to have a synergistic effect on detoxification.
Mechanism of action of hydroxocobalamin:
• Hydroxocobalamin combines with cyanide to form cyanocobalamin (vitamin B-12), which is renally cleared.
• Alternatively, cyanocobalamin may dissociate from cyanide at a slow enough rate to allow for cyanide detoxification by the mitochondrial enzyme rhodanese.

Reactive arthritis, (formerly known as Reiter’s syndrome), is an autoimmune condition that occurs after a bacterial infection of the gastrointestinal or urinary tract. It is categorized as a seronegative spondylarthritis because of its association with HLA-B27. Reactive arthritis primarily affects young men and usually presents with musculoskeletal or extra‑articular symptoms. The characteristic triad consists of arthritis, conjunctivitis, and urethritis. The diagnosis is based on clinical features such as patient history and physical examination; there are no specific tests for reactive arthritis. Treatment is primarily symptomatic and consists of the administration of NSAIDs, as most patients recover spontaneously. extraarticular dermatologic manifestations include skin lesions of the glans resembling psoriasis (balanitis circinata); hyperkeratinisation of the palms and soles (keratoderma blenorrhagicum), oral ulcers. Other STDs including HIV, syphilis have different presentations. Psoriatic arthritis is not commonly associated with urethritis and conjunctivitis.

Spinal cord hemisection, also known as Brown-Sequard syndrome, is associated with symptoms affecting one spinothalamic and one corticospinal tract. Symptoms include ipsilateral paralysis, loss of vibration and position sense, and hyperreflexia below the level of the lesion. Contralateral loss of pain and temperature sensation is also seen, usually beginning 2-3 segments below the level of the lesion.

The diagnosis of Hodgkin disease requires the identification of Reed-Sternberg cells in a characteristic cellular background. The normal cell of origin for the Reed-Sternberg cells remains unclear, with the predominance of evidence indicating a B or T lymphocyte.

The ECG findings are suggestive of anterior myocardial infarction and the most likely artery affected is the left anterior descending artery. Occlusion of the right coronary artery will be shown by ST elevation in lead II, III, aVF and occlusion of the circumflex artery will show changes in leads I, aVL, V5 and V6. To have ST elevation, there should be complete occlusion of the artery.

Tumour marker CA 125 is mostly associated with primary peritoneal cancer and ovarian cancer. It can be used to monitor response to chemotherapy, alongside regular CT scans.

Tumour markers can be divided into:
1. Monoclonal antibodies
CA 125: Ovarian cancer, primary peritoneal cancer
CA 19-9: Pancreatic cancer
CA 15-3: Breast cancer

2. Tumour specific antigens
Prostate specific antigen (PSA): Prostatic carcinoma
Alpha-feto protein (AFP): Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA): Colorectal cancer
S-100: Melanoma, schwannomas
Bombesin: Small cell lung carcinoma, gastric cancer

3. Enzymes
Alkaline phosphatase (ALP)
Neuron specific enolase (NSE)

4. Hormones
Calcitonin
Antidiuretic hormone (ADH)
Human chorionic gonadotropin (hCG)

Characteristic findings on patients suffering from diphtheria are the grey membrane on the uvula and tonsils together with the low grade fever and dyspnoea. It’s of great importance that the patient has recently been to India where there is a know prevalence.

Basal cell carcinoma is usually located on sun exposed sites. It has got many variants and clinically it presents as a slow growing mass/nodule with rolled margins and an ulcerated base.

Pseudogout is a paroxysmal joint inflammation due to calcium pyrophosphate crystal deposition (calcium pyrophosphate dihydrate). Arthrocentesis should be performed, especially in acute cases.
Polarized light microscopy: detection of rhomboid-shaped, positively birefringent CPPD crystals.
Synovial fluid findings: 10,000-50,000 WBCs/μL with > 90% neutrophils.
X-ray findings: cartilage calcification of the affected joint (chondrocalcinosis).
Fibrocartilage (meniscus, annulus fibrosus of intervertebral disc) and hyaline cartilage (joint cartilage) may be affected.

Alveolar haemorrhage (AH) is a rare, but serious manifestation of SLE. It may occur early or late in disease evolution. Extrapulmonary disease may be minimal and may be masked in patients who are already receiving immunosuppressants for other symptoms of SLE.

DLCO or TLCO (diffusing capacity or transfer factor of the lung for carbon monoxide (CO)) is the extent to which oxygen passes from the air sacs of the lungs into the blood.
Factors that can increase the DLCO include polycythaemia, asthma (can also have normal DLCO) and increased pulmonary blood volume as occurs in exercise. Other factors are left to right intracardiac shunting, mild left heart failure (increased blood volume) and alveolar haemorrhage (increased blood available for which CO does not have to cross a barrier to enter).

The pattern of muscle involvement seen with quadriceps and long-finger flexors is characteristic of inclusion body myositis, an inflammatory myopathy. Polymyositis is likely to cause a predominantly proximal weakness, associated with muscle pain. The signs and symptoms are not consistent with upper cord compression, as there would likely be sensory signs, reflex changes, and possible urinary symptoms. Motor neuron disease cannot be ruled out, but there are no findings of upper motor neuron or bulbar features.

Severe vitamin C deficiency results in scurvy, a disorder characterized by hemorrhagic manifestations and abnormal osteoid and dentin formation.
Vitamin C plays a role in collagen, carnitine, hormone, and amino acid formation. It is essential for bone and blood vessel health and wound healing and facilitates recovery from burns. Vitamin C is also an antioxidant, supports immune function, and facilitates the absorption of iron (see table Sources, Functions, and Effects of Vitamins).
Dietary sources of vitamin C include citrus fruits, tomatoes, potatoes, broccoli, strawberries, and sweet peppers. (See also Overview of Vitamins.)

Among the given options, an addiction to opiates is considered the strongest risk factor for committing suicide.

Other options:
Being a female – Being male is one of the most significant risk factors for suicide.
Being married – Having family support is an important protective factor for suicide.
Having five children – Having children at home is thought to be a protective factor.
Having never seen a general practitioner – Having a chronic mental or physical condition is however a risk factor for suicide.

Risk factors of suicide:
There are several factors shown to be associated with an increased risk of suicide:
Male sex
History of deliberate self-harm
Alcohol or drug misuse
History of mental illness (depression, schizophrenia)
History of chronic disease
Advancing age
Unemployment or social isolation/living alone
Being unmarried, divorced or widowed
Previous attempt to commit suicide.

Signs pointing towards suicidal intension:
Efforts to avoid discovery
Planning
Leaving a written note
Final acts such as sorting out finances
Violent method

Protective factors against suicide:
Family support
Having children at home
Religious belief