Patiromer

Key takeaways

Patiromer belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Patiromer to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Patiromer from memory before moving on to harder problems.

Reference excerpt

Patiromer, sold under the brand name Veltassa, is a medication used to treat high blood potassium. It is taken by mouth. It works by binding potassium in the GI tract. Common side effects include constipation, low blood magnesium, and abdominal pain. It was approved for medical use in the United States in October 2015, and in the European Union in July 2017.

Medical uses Patiromer is used for the treatment of hyperkalemia, but not as an emergency treatment for life-threatening hyperkalemia, as it acts relatively slowly. Such a condition needs other kinds of treatment, for example calcium infusions, insulin plus glucose infusions, salbutamol inhalation, and hemodialysis. Typical reasons for hyperkalemia are chronic kidney disease and application of drugs that inhibit the renin–angiotensin–aldosterone system (RAAS) – e.g. ACE inhibitors, angiotensin II receptor antagonists, or potassium-sparing diuretics – or that interfere with kidney function in general, such as nonsteroidal anti-inflammatory drugs (NSAIDs).

Adverse effects Patiromer was generally well tolerated in studies. Side effects that occurred in more than 2% of patients included in clinical trials were mainly gastro-intestinal problems such as constipation, diarrhea, nausea, and flatulence, and also hypomagnesemia (low levels of magnesium in the blood) in 5% of patients, because patiromer binds magnesium in the gut as well.

Interactions Patiromer was tested for drug-drug interactions with 28 drugs and showed binding or interaction with 14 of these drugs. This could reduce their availability and thus effectiveness, wherefore patiromer has received a boxed warning by the US Food and Drug Administration (FDA), telling patients to wait for at least six hours between taking patiromer and any other oral drugs. Of the 14 drugs that did show an interaction in vitro, 12 were selected for further testing in phase 1 studies in healthy volunteers to assess whether the results seen in vitro translated into an effect in people. These studies showed patiromer did not alter the absorption of nine of the 12 drugs when co-administered. Patiromer reduced absorption of three drugs when co-administered, however, there was no interaction when patiromer and these three drugs were taken 3 hours apart. This information was submitted to the FDA in the form of a supplemental New Drug Application (sNDA) and as a result, in November 2016 the FDA approved the removal of the boxed warning regarding the separation of patiromer and other oral medications. The updated label recommends patients take patiromer at least three hours before or three hours after other oral medications.

Pharmacology

Mechanism of action Patiromer works by binding free potassium ions in the gastrointestinal tract and releasing calcium ions for exchange, thus lowering the amount of potassium available for absorption into the bloodstream and increasing the amount that is excreted via the feces. The net effect is a reduction of potassium levels in the blood serum. Lowering of potassium levels is detectable seven hours after administration. Levels continue to decrease for at least 48 hours if treatment is continued, and remain stable for 24 hours after administration of the last dose. After this, potassium levels start to rise again over a period of at least four days.

Pharmacokinetics Patiromer is not absorbed from the gut, is not metabolized, and is excreted in unchanged form with the feces.

Chemistry The substance is a cross-linked polymer of 2-fluoroacrylic acid with divinylbenzenes and 1,7-octadiene. It is used in form of its calcium salt (ratio 2:1) and with sorbitol (one molecule per two calcium ions or four fluoroacrylic acid units), a combination called patiromer sorbitex calcium.

Patiromer sorbitex calcium is an off-white to light brown, amorphous, free-flowing powder. It is insoluble in water, 0.1 M hydrochloric acid, heptane, and methanol.

History In a Phase III multicenter clinical trial including 237 patients with hyperkalemia under RAAS inhibitor treatment, 76% of participants reached normal serum potassium levels within four weeks. After subsequent randomization of 107 responders into a group receiving continued patiromer treatment and a placebo group, re-occurrence of hyperkalemia was 15% versus 60%, respectively.

Society and culture

Legal status The US FDA approved patiromer in October 2015. It was approved for use in the European Union in July 2017.

References

Illustrations

Worked examples

Example 1 — a first encounter with Patiromer

Start with the simplest possible case. Write down what Patiromer claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Patiromer before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Patiromer ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Patiromer

In research: Patiromer appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Patiromer in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Patiromer is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nephrology procedures, Organic polymers, Potassium, so understanding it makes those chapters shorter.
In everyday life: Look for Patiromer outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Patiromer in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Patiromer means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Patiromer out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Patiromer in simple terms?

Patiromer, sold under the brand name Veltassa, is a medication used to treat high blood potassium. It is taken by mouth.

Why does Patiromer matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Patiromer?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Patiromer.