Quinapril 

Insufficiency in kidney function

As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function may be anticipated in susceptible individuals. In patients with severe heart failure whose renal function may depend on the activity of the renin-angiotensin-aldosterone system, treatment with ACE inhibitors, including Quinapril, may be associated with oliguria and/or progressive azotemia and rarely acute renal failure and/or death.

In studies of clinical hypertensive patients suffering from either bilateral or unilateral renal arterial stenosis, the levels of blood urea nitrogen, as well as serum creatinine levels, have been noted in some patients receiving ACE inhibitor treatment.

These elevations were generally and were reversible after discontinuation of the ACE inhibitor or diuretic treatment. In these individuals, the renal functions must be assessed during an initial couple of weeks of therapy.

Certain patients suffering from hypertension or heart failure who have no preexisting renal disease have experienced increased blood urea and serum creatinine. These are usually small and temporary, especially when Quinapril was administered in conjunction with diuretics. It is more likely to occur in patients suffering from existing kidney impairment. Reduction in dosage or stopping any diuretic or Quinapril might be required.

The evaluation of patients suffering from hypertension or heart failure must always include a thorough assessment of kidney performance 

Hyperkalemia

In clinical studies in clinical trials, high levels of hyperkalemia (serum potassium >=5.8 mg/L) was seen in about 2percent of patients taking Quinapril. In the majority of cases, the elevated levels of serum potassium were unrelated and were able to be cured despite the continued treatment. Less than 0.1% of patients quit treatment because of hyperkalemia.

The risk factors that contribute to developing hyperkalemia are diabetes mellitus, renal insufficiency as well as the usage of other drugs that increase the levels of potassium in the serum. Check the levels of potassium in these sufferers 

Cough

Most likely because of the suppression of the degradation of bradykinin endogenous, non-productive cough has been observed for all ACE inhibitors, and always resolved following the cessation of therapy. ACE inhibitor-related cough must be considered as a differentiating classification of the cough.

Surgery/anesthesia

For patients who undergo major surgery or under anesthesia using agents that cause hypotension, Quinapril can block angiotensin II production due to the release of renin in response to compensatory. If hypotension develops and is thought to be the result of the mechanism mentioned above, then it may be corrected by expanding the volume.

Pregnancy

Women who are pregnant should inform patients who are childbearing about the negative effects of being exposed to Quinapril during pregnancy. Discuss possible treatment options with women who plan to get pregnant. Encourage patients to report the pregnancy to their doctors whenever they can.

Angioedema

Angioedema and laryngeal edema is a common side effect of ACE inhibitors, particularly after initial dosage. Inform patients to report immediately any symptoms or signs that suggest angioedema (swelling of the face eyelids, extremities or lips, tongue difficulties swallowing, difficulty breathing) and to discontinue using the medication until they’ve spoken with their doctor

Hypotension that is symptomatic

Be aware that lightheadedness could occur, especially in the initial few days of treatment with Quinapril and must be reported directly to a doctor. If syncope is observed then advise patients to stop taking the medication until they’ve consulted their doctor.

All patients should be aware that insufficient drinking of fluids or excessive sweating vomiting, diarrhea or perspiration could cause an extreme decrease in blood pressure because of the reduction in fluid volume and the resulting effects of syncope and lightheadedness.

If you are who plan to undergo any procedure or anesthesia inform their doctor who prescribes an ACE inhibitor.

Hyperkalemia

Do not advise patients to use sodium supplements, salt replacements or potassium that contain potassium without consulting with their doctor 

Neutropenia

Inform patients to immediately notify you of any signs of an infection (eg sore throat or fever) that could indicate neutropenia.

Notification: As with other medications, specific advice for patients who are treated with Quinapril is advised. This information is designed to help ensure the safe and efficient usage of this medication. It is not a comprehensive list of every possible negative or desired adverse effect.

Diuretic therapy in conjunction with diuretic therapy.

Similar to similar ACE inhibitors, people taking diuretics, in particular, those on diuretic therapy that was recently initiated can occasionally suffer a drastic reduction in blood pressure following the introduction of treatment with Quinapril. The risk of hypotensive reactions associated with Quinapril could be mitigated by either stopping the diuretic or slowly increasing the intake of salt prior to starting the treatment using Quinapril. If it’s not feasible to stop diuretics, the initial dose of quinapril must be decreased.

Agents that increase the level of potassium in the bloodstream.

The coadministration of Quinapril and other medications that increase potassium levels in the serum can cause hyperkalemia. Monitor serum potassium in such patients.

Tetracycline and various other medications that are in a relationship with magnesium

The simultaneous administration of tetracycline and Quinapril decreased the absorption rate of tetracycline from 28%-37%, which could be due to its high content of magnesium found in Quinapril tablets. This interaction must be taken into consideration when prescribing Quinapril in combination with tetracycline, or any other drug that is in a relationship with magnesium.

Lithium

Higher levels of serum lithium and signs of lithium-related toxicity have been documented in patients who are receiving concurrent lithium as well as ACE inhibitor treatment. The drugs must be administered with care and regular surveillance of the serum lithium levels is advised. If a diuretic is utilized, it can raise the chance of toxicity to lithium.

Gold

Nitritoid reactions (symptoms include facial flushing nausea vomiting, hypotension, and facial flushing) have been reported only in patients receiving treatment with injection-able gold (sodium aurothiomalate) as well as concomitant ACE inhibitor treatment.

Non-steroidal anti-inflammatory drugs

For patients who are old and depleted in their volume (including diuretic patients) or have impaired renal function, the co-administration of NSAIDs such as selective COX-2 inhibitors, along with ACE inhibitors, like quinapril can cause an impairment of renal function and even severe renal dysfunction. The effects of these are typically reversible. Check the renal function regularly in patients taking quinapril as well as NSAID treatment.

The antihypertensive action is a result of ACE inhibitors, such as quinapril could be reduced by NSAIDs.

Agents that block mTOR, or other drugs that cause angioedema.

Patients who are taking mTOR inhibitors in conjunction with (e.g. the Temsirolimus) treatment or a neprilysin antagonist could be at greater risk of angioedema.

Other agents

Studies of the drug interaction of Quinapril and other agents revealed:

• Multiple-dose therapy using propranolol and cimetidine have no impact on the pharmacokinetics of single doses of Quinapril.
• The anticoagulant action from dose warfarin (measured by prothrombin duration) was not significantly altered with quinapril coadministration twice daily.
• Quinapril treatment has not affected the dosage of digoxin’s pharmacokinetics.
• No pharmacokinetic interactions were observed when individual doses of Quinapril, as well as hydrochlorothiazide, were given concurrently.
• The co-administration of multiple doses of 10 mg of atorvastatin in combination with the Quinapril dosage of 80 mg produced little or no change in the pharmacokinetic parameters at steady-state of the atorvastatin.