Depression is a prevalent psychiatric issue in patients with Parkinson’s disease, with approximately 40% of individuals experiencing it, despite dementia being a common comorbidity.

Parkinson’s disease is a progressive neurodegenerative condition that occurs when dopaminergic neurons in the substantia nigra degenerate. This leads to a classic triad of symptoms, including bradykinesia, tremor, and rigidity, which are typically asymmetrical. The disease is more common in men and is usually diagnosed around the age of 65. Bradykinesia is characterized by a poverty of movement, shuffling steps, and difficulty initiating movement. Tremors are most noticeable at rest and typically occur in the thumb and index finger. Rigidity can be either lead pipe or cogwheel, and other characteristic features include mask-like facies, flexed posture, and micrographia. Psychiatric features such as depression, dementia, and sleep disturbances may also occur. Diagnosis is usually clinical, but if there is difficulty differentiating between essential tremor and Parkinson’s disease, 123I‑FP‑CIT single photon emission computed tomography (SPECT) may be considered.

Investigations for Acute Interstitial Nephritis

Acute interstitial nephritis (AIN) can present with non-specific symptoms of acute kidney dysfunction, such as nausea, vomiting, and malaise. A decline in kidney function is typical, and a raised creatinine on U+ESs may already be present. A drug history, along with a raised eosinophilia on full blood count (FBC), can aid in the diagnosis of AIN. Common causes of AIN include drugs like proton-pump inhibitors, non-steroidal anti-inflammatories, and antibiotics, as well as autoimmune disorders or other systemic diseases.

Antinuclear antibody (ANA) testing should be performed to rule out systemic lupus erythematosus (SLE), which can coexist with AIN. However, a positive ANA test alone would not confirm a diagnosis of AIN.

Urinary dipstick testing for protein is not useful in diagnosing AIN, as patients with AIN typically do not have protein in their urine. Nephrotic syndrome can occur as a rare complication of AIN.

Renal biopsy may be necessary to confirm the diagnosis of AIN, as it is characterized by an inflammatory infiltrate in the kidney interstitium. However, if the patient’s condition is drug-induced, a renal biopsy may not be required if a raised creatinine and eosinophil count, along with the drug history, are sufficient for diagnosis.

Chest X-ray (CXR) may be necessary to investigate other potential causes of AIN, such as sarcoidosis. If sarcoidosis is suspected and the CXR is inconclusive, a computed tomography chest may be performed. However, if the patient has been exposed to a drug that predisposes them to AIN, a diagnosis of drug-induced interstitial nephritis is more likely than an underlying systemic disease.

Cardiomyopathy can be caused by anthracyclines such as doxorubicin.

Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin, degrade preformed DNA and can lead to lung fibrosis. Anthracyclines, such as doxorubicin, stabilize the DNA-topoisomerase II complex and inhibit DNA and RNA synthesis, but can also cause cardiomyopathy. Antimetabolites, like methotrexate, inhibit dihydrofolate reductase and thymidylate synthesis, leading to myelosuppression, mucositis, liver fibrosis, and lung fibrosis. Fluorouracil (5-FU) is a pyrimidine analogue that induces cell cycle arrest and apoptosis by blocking thymidylate synthase, but can also cause myelosuppression, mucositis, and dermatitis. Cytarabine is a pyrimidine antagonist that interferes with DNA synthesis specifically at the S-phase of the cell cycle and inhibits DNA polymerase, but can also cause myelosuppression and ataxia. Drugs that act on microtubules, like vincristine and vinblastine, inhibit the formation of microtubules and can cause peripheral neuropathy, paralytic ileus, and myelosuppression. Docetaxel prevents microtubule depolymerisation and disassembly, decreasing free tubulin, but can also cause neutropaenia. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I which prevents relaxation of supercoiled DNA, but can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin, cause cross-linking in DNA and can lead to ototoxicity, peripheral neuropathy, and hypomagnesaemia. Hydroxyurea (hydroxycarbamide) inhibits ribonucleotide reductase, decreasing DNA synthesis, but can also cause myelosuppression.

Thiazides can cause lithium toxicity, while sodium bicarbonate and aminophylline can lower plasma levels of lithium.

Understanding Lithium Toxicity

Lithium is a medication used to stabilize mood in individuals with bipolar disorder and as an adjunct in refractory depression. However, it has a narrow therapeutic range of 0.4-1.0 mmol/L and a long plasma half-life, making it crucial to monitor its levels in the blood. Lithium toxicity occurs when the concentration exceeds 1.5 mmol/L, which can be caused by dehydration, renal failure, and certain medications such as diuretics, ACE inhibitors, NSAIDs, and metronidazole.

Symptoms of lithium toxicity include a coarse tremor, hyperreflexia, acute confusion, polyuria, seizures, and even coma. It is important to manage toxicity promptly, as mild to moderate cases may respond to volume resuscitation with normal saline. However, severe cases may require hemodialysis to remove excess lithium from the body. Some healthcare providers may also use sodium bicarbonate to increase the alkalinity of the urine and promote lithium excretion, although evidence supporting its effectiveness is limited.

In summary, understanding lithium toxicity is crucial for healthcare providers and individuals taking lithium. Monitoring lithium levels in the blood and promptly managing toxicity can prevent serious complications and ensure the safe use of this medication.

Management of Sickle Cell Disease: Antibiotic Prophylaxis, B12 and Iron Supplementation, and Malaria Prophylaxis

Sickle cell disease is a condition that increases the risk of infections, particularly pneumococcal infections, respiratory tract infections, urinary tract infections, and osteomyelitis. To prevent severe infections or sepsis, the National Institute for Health and Care Excellence (NICE) recommends lifelong antibiotic prophylaxis with penicillin V or amoxicillin for people with sickle cell disease, starting ideally at three months of age. Pneumococcal vaccination every five years is also crucial. Co-amoxiclav is not the antibiotic of choice for prophylaxis. B12 supplementation is indicated only if a person with sickle cell disease has B12 deficiency. Folate supplementation is recommended for all people with sickle cell anaemia due to high folate turnover associated with haemolysis. Lifelong iron supplementation is not recommended unless there is proven iron deficiency that would require 3-month supplements rather than lifelong treatment. Finally, sickle cell disease does not protect against malaria, and people with sickle cell disease planning to travel to an area where malaria is endemic should take the standard recommended malaria prophylaxis for that area.

Gliclazide is not the preferred initial treatment for type 2 diabetes. Due to the patient’s inability to tolerate metformin and a QRISK score of >10, there is now a higher likelihood of cardiovascular disease.

NICE updated its guidance on the management of type 2 diabetes mellitus (T2DM) in 2022, reflecting advances in drug therapy and improved evidence regarding newer therapies such as SGLT-2 inhibitors. The first-line drug of choice remains metformin, which should be titrated up slowly to minimize gastrointestinal upset. HbA1c targets should be agreed upon with patients and checked every 3-6 months until stable, with consideration for relaxing targets on a case-by-case basis. Dietary advice includes encouraging high fiber, low glycemic index sources of carbohydrates and controlling intake of foods containing saturated fats and trans fatty acids. Blood pressure targets are the same as for patients without type 2 diabetes, and antiplatelets should not be offered unless a patient has existing cardiovascular disease. Only patients with a 10-year cardiovascular risk > 10% should be offered a statin, with atorvastatin 20mg as the first-line choice.

Differential Diagnosis for a Patient with Abnormal Full Blood Count Results

When a patient presents with abnormal full blood count (FBC) results, it is important to consider a range of potential diagnoses. In this case, the patient has neutrophilia and atypical lymphocytes, indicating an acute bacterial infection. Other potential diagnoses, such as chronic myeloid leukaemia, tuberculosis, cytomegalovirus infection, and pregnancy, can be ruled out based on the absence of key symptoms and blood film findings. Clinical prediction scores can be used to aid in antibiotic stewardship. It is important to consider all potential diagnoses and conduct further testing as needed to ensure accurate diagnosis and appropriate treatment.

The preferred treatment for gonococcal infections is a single intramuscular dose of ceftriaxone, with the dosage based on the patient’s weight. This medication is highly effective against susceptible N. gonorrhoeae and more effective than oral cephalosporins. A test of cure is necessary after treatment to ensure the infection has been cleared. Ciprofloxacin should only be used if the organism’s susceptibility to the antibiotic is known. Dual antibiotic use is no longer recommended, but presumptive treatment for chlamydia may be administered if the patient’s sexual history or symptoms suggest co-infection. Intravenous antibiotics are not necessary for uncomplicated cases, but severe cases of pelvic inflammatory disease may require hospitalization and intravenous antibiotics. Penicillin is not indicated for gonorrhoea treatment due to high antimicrobial resistance.

Understanding Coeliac Disease: Symptoms, Diagnosis, and Treatment

Coeliac disease (CD) is a common autoimmune disorder that affects almost 1% of individuals in developed countries. It is triggered by gluten and related prolamins present in wheat, rye, and barley, and primarily affects the small intestine, leading to flattening of the small intestinal mucosa. CD can present in various ways, including typical GI symptoms, atypical symptoms, or no symptoms at all. Diagnosis is made through serology tests for specific autoimmune markers, and treatment involves a lifelong avoidance of gluten ingestion.

Other potential diagnoses, such as travellers’ diarrhoea, growth hormone deficiency, hypothyroidism, and severe combined immunodeficiency, have different clinical presentations and are not consistent with this patient’s symptoms. Understanding the symptoms, diagnosis, and treatment of CD is crucial for proper management and improved quality of life for affected individuals.

The latest NICE guidelines classify any infant under 3 months old with a temperature exceeding 38ºC as a ‘red’ feature, necessitating immediate referral to a paediatrician. While some seasoned GPs may opt not to adhere to this recommendation, it is crucial to stay informed about recent examination guidelines.

The NICE Feverish illness in children guidelines were introduced in 2007 and updated in 2013. These guidelines use a ‘traffic light’ system to assess the risk of children under 5 years old presenting with a fever. It is important to note that these guidelines only apply until a clinical diagnosis of the underlying condition has been made. When assessing a febrile child, their temperature, heart rate, respiratory rate, and capillary refill time should be recorded. Signs of dehydration should also be looked for. Measuring temperature should be done with an electronic thermometer in the axilla if the child is under 4 weeks old or with an electronic/chemical dot thermometer in the axilla or an infra-red tympanic thermometer.

The risk stratification table includes green for low risk, amber for intermediate risk, and red for high risk. If a child is categorized as green, they can be managed at home with appropriate care advice. If they are categorized as amber, parents should be provided with a safety net or referred to a pediatric specialist for further assessment. If a child is categorized as red, they should be urgently referred to a pediatric specialist. It is important to note that oral antibiotics should not be prescribed to children with fever without an apparent source, and a chest x-ray does not need to be routinely performed if a pneumonia is suspected but the child is not going to be referred to the hospital.