Appreciate your inviting me into a conversation.
Starting point must be a solid diagnosis. An important study on this question found that 50% of folks diagnosed with Cluster did not have it, even as the immediate symptom picture lead to the Dx of Cl. Point being: self-diagnosis is not wise.
Compounding the problem: there are a number of serious disorders which mimic Cluster but which are not headache disorders. Sort thru this issue takes a doc with some skill/experience (Next is not to scare you but to give some idea of how complex making a Dx can be. Just scan his material to get a sense of the potentials we are dealing with. [Link to: cluster-LIKE headache:
IN: "Medications, Treatments, Therapies --> "Important Topics" --> "Cluster-LIKE headache"]
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So, given your restricted resources and need for a well grounded diasnosis before starting long term treatment, explore your options to find a headache specialist. At the least, one who will Dx you and then turn you back to your local docs for treatment and superivison of your treatment.
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LOCATING HEADACHE SPECIALIST
1. Yellow Pages phone book: look for "Headache Clinics" in the M.D. section and look under "neurologist" where some docs will list speciality areas of practice.
2. Call your hospital/medical center. They often have an office to assist in finding a physician. You may have to ask for the social worker/patient advocate.
3. Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

or

; On-line screen to find a physician.
4. Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

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Look for "Physician Finder" search box. They will send a list of M.D.s for your state.I suggest using this source for several reasons: first, we have read several messages from people who, even seeing neurologists, are unhappy with the quality of care and ATTITUDES they have encountered; second, the clinical director of the Jefferson (Philadelphia) Headache Clinic said, in late 1999, that upwards of 40%+ of U.S. doctors have poor training in treating headache and/or hold attitudes about headache ("hysterical female disorder") which block them from sympathetic and effective work with the patient; third, it's necessary to find a doctor who has experience, skill, and a set of attitudes which give hope of success. This is the best method I know of to find such a physician.
5. Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

or

NEW certification program for "Headache Medicine" by the United Council for Neurologic Subspecialties, an independent, non-profit, professional medical organization.
Since this is a new program, the initial listing is limited and so it should be checked each time you have an interest in locating a headache doctor.
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Assuming you must use a local doc. Many of us have beenin this situation and have been blessed with a doc who had an open ego, willing to accept medical information from us to use to our benefit.
So, just some basic medical material for you to print and prepae to give to a local doc who needs help treating you.
1. Print the PDF file, below. (Have a more complex version of this article if needed. Just ask.)
2.
Three sites which are worth your attention: medical literature, films, plus the expected information
about CH.
Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

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Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

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Search under "cluster headache"
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Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to

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Full of articles, blogs, book: written by one of the best headache docs in the Chicago area.
Worth exploring. The latest book is in e-book edition, $10; comprehensive and worth buying for
a careful read.
[re. headachedrugs: site of one of the best headache docs in the country; in the Chicago area. GIVE this site address to any doc ou see. Much of the material is aimed at doctors. The e-book noted <info at the site> is loaded with dense stuff for physicians. Direct any doc you see to this web site and this e-book.]
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You note having low BP which excludes using the best preventive med for Cluster we have, Verapamil. So, use the PDF file to explore options with a doc.
The overall approach to control Cluster is: Prednisone for a few DAYS to kill attacks WHILE AT THE SAME TIME stating to use a long acting preventive med to block/reduce future attacks; and an abortive to kill attacks which sneak thru.
Since you can't use Imitrex, print following and give to your doc. Some of us have had absolute relief with it.
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Headache 2001 Sep;41(8):813-6
Olanzapine as an Abortive Agent for Cluster Headache.
Rozen TD.
Department of Neurology, Jefferson Headache Center/Thomas Jefferson University Hospital, Philadelphia, Pa.
OBJECTIVE: To evaluate olanzapine as a cluster headache abortive agent in an open-label trial. BACKGROUND: Cluster headache is the most painful headache syndrome known. There are very few recognized abortive therapies for cluster headache and fewer for patients who have contraindications to vasoconstrictive drugs. METHODS: Olanzapine was given as an abortive agent to five patients with cluster headache in an open-label trial. THE INITIAL OLANZAPINE DOSE WAS 5 MG, AND THE DOSE WAS INCREASED TO 10 MG IF THERE WAS NO PAIN RELIEF. THE DOSAGE WAS DECREASED TO 2.5 MG IF THE 5-MG DOSE WAS EFFECTIVE BUT CAUSED ADVERSE EFFECTS. To be included in the study, each patient had to treat at least two attacks with either an effective dose or the highest tolerated dose. RESULTS: Five patients completed the investigation (four men, one woman; four with chronic cluster, one with episodic cluster). Olanzapine reduced cluster pain by at least 80% in four of five patients, and TWO PATIENTS BECAME HEADACHE-FREE AFTER TAKING THE DRUG. Olanzapine typically alleviated pain within 20 minutes after oral dosing and treatment response was consistent across multiple treated attacks. The only adverse event was sleepiness. CONCLUSIONS: Olanzapine appears to be a good abortive agent for cluster headache. IT ALLEVIATES PAIN QUICKLY AND HAS A CONSISTENT RESPONSE ACROSS MULTIPLE TREATED ATTACKS. IT APPEARS TO WORK IN BOTH EPISODIC AND CHRONIC CLUSTER HEADACHE.
PMID 11576207 PubMed
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Olanzapine has a brand name of "Zyprexa" and is a antipsychotic. Don't be put off by this primary usage. Several of the drugs used to treat CH are cross over applications, that is, drugs approved by the FDA for one purpose which are found to be effective with unrelated conditions--BJ.
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This is enough for you for one session! Stay in touch.